SEARCH · Search PubMed

Results for “SPACE”

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.

SourceResearch connectionFrom yearThrough year

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

At least 1,621 records · Page 90Linked to original sources

PubMed1976

Adenoid cystic carcinoma of minor salivary gland. Histochemical and electron microscopic studies of cystlike space.

Five cases of adenoid cystic carcinoma of minor salivary glands were studied. The mucoid material in the characteristic cystlike space of this neoplasm was distaseresistant periodic acid-Schiff (PAS)--positive, alcain blue-positive, toluidine blue-positive, and mucicarmine-positive. Verhoeff-Van Gieson's method and Weighert's method did not reveal elastic tissue in the cystlike spaces. Mallory's method revealed that a central core in cystlike spaces was similar in stainability to collagen. Wilder's method did not reveal reticular fibers in these spaces. Electron microscopy revealed three readily recognizable zones: a juxtacellular zone of a network of replicated basal lamina, and intermediate zone of stellate granules of mucoid material, and a central core of densely packed aperiodic filaments or collagen fibrils. The histogenesis of cystlike spaces and their realtionship with biologic behaviors of the neoplasm were discussed.

Carcinoma, Adenoid Cystic↗

PubMed1993

Unilateral carpal tunnel syndrome and space-occupying lesions.

To assess the association between unilateral carpal tunnel syndrome and space-occupying lesions, 128 patients have been reviewed. They were divided into bilateral, subclinical (unilateral signs and symptoms, and bilateral slowing in the median nerve conduction) and unilateral carpal tunnel syndrome. Space-occupying lesions were investigated on the basis of physical examination and wrist imaging using plain radiographs and ultrasonograms. Of 20 patients with unilateral carpal tunnel syndrome, space-occupying lesions were found in seven (occult ganglion in five and occult calcified mass in two). In contrast, none of 89 patients with bilateral carpal tunnel syndrome and 19 with subclinical carpal tunnel syndrome had space-occupying lesions. We conclude that careful examination and wrist imaging on suspicion of local pathology, especially a space-occupying lesion, are needed when the condition is unilateral and the aetiology is not clear from the history and on physical examination.

Adult↗

PubMed1995

Concepts of disability: the Activity Space Model.

This paper describes a new conceptual framework for functional assessment, the Activity Space Model (ASM). According to this model, functional impairments may lead to restrictions in an individual's activity space, a multidimensional space that represents human potential for activity. For each elementary ability, restrictions in the corresponding dimension of the activity space can be evaluated by deriving a difficulty curve that depicts the relationship between the level of performance and the psychophysical cost of activity. The effect of disease on daily functioning is explained in terms of a tradeoff between the psychophysical cost and the value of each act of behavior to the disabled individual. These two constructs are measured on the same scale and expressed in units of difficulty. The location of each task within the activity space in relation to the difficulty curve determines whether it will be performed or avoided at a given point in time. The ASM has both theoretical and practical implications. It offers a new, integrated perspective on disability and suggests new strategies for developing and evaluating functional assessment measures.

Disability Evaluation↗

PubMed1987

Blood volume and red cell space in tissues of the rainbow trout, Salmo gairdneri.

1. Whole body blood volume and red cell space of 22 tissues were measured in unanesthetized rainbow trout at 4, 12, 30, 60, 150 and 240 min after dorsal aortic injection of 51Cr-labeled red blood cells. 2. Apparent blood volume decreased during the initial 30 min after injection and increased thereafter. At 240 min the blood volume was 33.5 +/- 3.1 ml/kg body wt. 3. Tissue red cell space varied as a function of the interval between labeled red cell injection and tissue collection. Red cell space was highest in spleen followed by heart, kidney and liver. Lowest red cell spaces were found in stomach and red and white skeletal muscle. 4. Variability in blood volume and tissue red cell space over time suggests that caution should be exercised in the design of experiments that employ indicator dilution measurements to measure vascular volumes.

Animals↗

PubMed1985

A monaural space map in the guinea-pig superior colliculus.

Under anechoic conditions, a horizontal array of loudspeakers was used to investigate the representation of auditory space in the guinea-pig superior colliculus. We have previously demonstrated that in animals with both ears intact, there is a topographical representation of the azimuthal dimension of auditory space in the deep layers of this nucleus. In the present study, we have investigated the contribution of monaural and binaural cues to the generation of the auditory space map. Occlusion of one ear or unilateral cochlear destruction resulted in omnidirectional responses in all cells to white-noise stimuli more than 20 dB suprathreshold. The sensitivity of cells to the location of sound at or near threshold was, however, unchanged and we demonstrate the presence of a threshold, monaural auditory space map. This monaural space map was destroyed by removal of the contralateral pinna and concha which resulted in all cells responding best, at threshold, to sounds opposite the external auditory meatus. Measurements of cochlear microphonic (CM) potentials, although variable, revealed that the pinna and concha may result in location-specific changes in the spectral pattern at the tympanic membrane.

Animals↗

PubMed1990

Star volume of marrow space and trabeculae in iliac crest: sampling procedure and correlation to star volume of first lumbar vertebra.

The star volume is a new stereologic parameter which can describe structural changes of trabecular bone. It is defined as the mean volume of all the parts of an object which can be seen unobscured in all directions from a particular point inside the object. The mean is over all points inside the object. The parameter is only unbiased when Baddeley's vertical or isotropic sections are used. The star volume of the marrow space (V*m.space) and of the trabeculae (V*tr) was estimated on vertical sections obtained from the first lumbar vertebra and the iliac crest. The continued autopsy material presented was from 7 females and 11 males without malignant or metabolic bone diseases. The mean age was 52 years (range 7-87 years). The sampling procedure was as required for vertical sections and an anisotropic test system was used. A significant age-related increase was shown in marrow space star volume in both lumbar vertebra and iliac crest. The increase in lumbar vertebra marrow space star volume was significantly greater for women than for men. Moreover, a significant correlation was found between the marrow space star volume in lumbar vertebra and iliac crest (r = 0.72, 2p less than 0.01). No such relation was found for trabecular star volume which did not change with age. The results also revealed that marrow space star volume could be measured on conventional bone biopsies preferably, however, on two mutually perpendicular vertical section planes.

Adult↗

PubMed2005

Vascular anatomy of the presacral space: a fresh tissue cadaver dissection.

OBJECTIVE: To assess variability in the vascular structures of the presacral space and to estimate the risk of injury because of blind suture placement during sacral colpopexy. STUDY DESIGN: Ten fresh frozen female cadavers were evaluated. Three 0-polyester sutures were placed blindly through the peritoneum and around the midline of the anterior longitudinal ligament. The presacral space was dissected and the sutures examined for injury to vessels. The midline of the anterior longitudinal ligament was marked from the promontory to its inferior edge, and measurements were taken to the leading edge of vessels proximal to the presacral space. On a template, all vessels larger than 2 mm were drawn to scale and overlaid on the template. RESULTS: Unequivocal vascular injury was found in 5 cadavers because of blind sutures. Four injuries occurred to the middle sacral artery and 1 to the left common iliac vein. There was significant variability in location of vessels, particularly on the left side of the ligament. CONCLUSIONS: The vascular pattern of the presacral space is variable, and major vessels may deviate significantly from their expected positions. Surgeons should carefully expose this space prior to placing sutures during sacral colpopexy.

Arteries↗

PubMed2006

Streptococcus milleri infections of the pleural space: operative management predominates.

BACKGROUND: Management of patients with thoracic empyema ranges from tube thoracostomy drainage, with or without fibrinolytics, to operative intervention, with the optimal intervention remaining uncertain. Streptococcus milleri, typically a benign bacterium colonizing the oropharynx, has recently been reported as a potential pathogen in pneumonia and pleural space disease. Our initial experience indicated this infection, when in the pleural space, was particularly tenacious and often required major operative intervention to eradicate. Therefore, we hypothesized that patients with S milleri pleural space infections often require operative intervention as definitive treatment. METHODS: We reviewed all patients from June 17, 1999 to April 15, 2005 with S milleri infections at our level I academic trauma/acute care surgery department at a safety-net hospital. S milleri infections were diagnosed by thoracentesis, bronchoalveolar lavage, tube thoracostomy fluid, or intraoperative culture. RESULTS: Over the 70-month period evaluated, of 697 patients with S milleri infections, 39 patients had S milleri infections of the pleural space; 26 (67%) patients underwent operative intervention. The majority (72%) were men with a mean age of 46 (range 22 to 63); the underlying etiology in those patients requiring operation was pneumonia (26 patients; 67%), trauma (9 patients; 23%), postoperative infection (2 patients), foreign body ingestion (1 patient), and malignancy (1 patient). The vast majority of patients in the operative group were treated preoperatively with tube thoracostomy (88%) and antibiotics (96%). The average duration of chest tube drainage prior to operation was 4.4 days (95% confidence interval [CI] 2.6 to 6.2) and antibiotic treatment was 6.0 days (95% CI 3.8 to 8.2). Thirteen patients (50%) underwent video-assisted thoracoscopic surgery (VATS) and 13 patients required thoracotomy. VATS was performed more often when operative intervention occurred early (average hospital day 6.2) compared to initial thoracotomy or conversion from VATS to thoracotomy (average hospital day 9.8). Hospital length of stay was less in the operative group (average 24 days; 95% CI 17 to 31) than in the nonoperative group (34 days; 95% CI 19 to 49), discharge to home was greater in the operative group (77% vs. 16%), and mortality was less in operative group (0% vs. 23%). CONCLUSIONS: Despite attempts at nonoperative management, the majority of patients with a S milleri pleural space infection require operative intervention for definitive therapy. Patients diagnosed with S milleri empyema should be considered for early operative intervention due to the unrelenting nature of their infection. Operative treatment is associated with a shorter hospital length of stay, increased discharge to home, and decreased mortality.

Adult↗

PubMed2004

Animals' use of landmarks and metric information to reorient: effects of the size of the experimental space.

Disoriented children could use geometric information in combination with landmark information to reorient themselves in large but not in small experimental spaces. We tested fish in the same task and found that they were able to conjoin geometric and non-geometric (landmark) information to reorient themselves in both the large and the small space used. Moreover, fish proved able to reorient immediately when dislocated from a large to a small experimental space and vice versa, suggesting that they encoded the relative rather than the absolute metrics of the environment. However, fish tended to make relatively more errors based on geometric information when transfer occurred from a small to a large space, and to make relatively more errors based on landmark information when transfer occurred from a large to a small space. The hypothesis is discussed that organisms are prepared to use only distant featural information as landmarks.

Animals↗

PubMed2006

Systemically transferred hematopoietic stem cells home to the subretinal space and express RPE-65 in a mouse model of retinal pigment epithelium damage.

Stem cell regeneration of damaged tissue has recently been reported in many different organs. Since the loss of retinal pigment epithelium (RPE) in the eye is associated with a major cause of visual loss - specifically, age-related macular degeneration - we investigated whether hematopoietic stem cells (HSC) given systemically can home to the damaged subretinal space and express markers of RPE lineage. Green fluorescent protein (GFP) cells of bone marrow origin were used in a sodium iodate (NaIO(3)) model of RPE damage in the mouse. The optimal time for adoptive transfer of bone marrow-derived stem cells relative to the time of injury and the optimal cell type [whole bone marrow, mobilized peripheral blood, HSC, facilitating cells (FC)] were determined by counting the number of GFP(+) cells in whole eye flat mounts. Immunocytochemistry was performed to identify the bone marrow origin of the cells in the RPE using antibodies for CD45, Sca-1, and c-kit, as well as the expression of the RPE-specific marker, RPE-65. The time at which bone marrow-derived cells were adoptively transferred relative to the time of NaIO(3) injection did not significantly influence the number of cells that homed to the subretinal space. At both one and two weeks after intravenous (i.v.) injection, GFP(+) cells of bone marrow origin were observed in the damaged subretinal space, at sites of RPE loss, but not in the normal subretinal space. The combined transplantation of HSC+FC cells appeared to favor the survival of the homed stem cells at two weeks, and RPE-65 was expressed by adoptively transferred HSC by four weeks. We have shown that systemically injected HSC homed to the subretinal space in the presence of RPE damage and that FC promoted survival of these cells. Furthermore, the RPE-specific marker RPE-65 was expressed on adoptively transferred HSC in the denuded areas.

Animals↗

PubMed2005

Prognostic significance of parapharyngeal space venous plexus and marrow involvement: potential landmarks of dissemination for stage I-III nasopharyngeal carcinoma.

PURPOSE: To determine whether the parapharyngeal space venous plexus and marrow of the skull base bones are anatomic landmarks of the potential routes for the spread of disease for Stage I-III (American Joint Commission on Cancer 1997 staging system) nasopharyngeal carcinoma (NPC). METHODS AND MATERIALS: A total of 364 patients with NPC were enrolled in this study. The selection criteria were Stage I-III disease and primary radiotherapy at our hospital between 1990 and 2001. All patients had undergone MRI to evaluate the head-and-neck tumors. Patients who had undergone inadequate radiotherapy at a dose of <60 Gy and/or preradiotherapy chemotherapy before the imaging evaluation were excluded from the study. RESULTS: Of the 364 patients treated between 1990 and 2001, 163 (44.8%) had low-risk Stage I-III NPC (without parapharyngeal space extension or T3 disease). The 5-year distant metastasis-free survival rate, with and without adjuvant chemotherapy, was 97% and 96%, respectively. The remaining 201 patients had Stage II-III with parapharyngeal space extension or T3 disease. Their 5-year recurrence-free survival rate, with and without adjuvant chemotherapy, was 76.8% and 53.2% (p = 0.01), respectively. CONCLUSION: Our findings suggest that the risk of distant metastasis in Stage I-III NPC patients without parapharyngeal space extension or T3 disease is extremely low. Invasion into the parapharyngeal space venous plexus and marrow of the skull base bones is associated with distant metastasis, and involvement of these anatomic sites is considered a potential route for hematogenous disease spread in patients with Stage I-III NPC.

Adult↗

PubMed2006

Reconstruction of thumb loss complicated by skin defects in the thumb-index web space by combined transplantation of free tissues.

OBJECTIVE: To introduce a new technique of 1-stage reconstruction for thumb loss complicated by thumb-index web space contracture and to report its clinical effectiveness. METHODS: From November 1994 to September 2004 there were 11 patients with thumb loss and contracture in the thumb-index web space who had a combined transplantation of free tissues to reconstruct the missing thumb and to rebuild the web space. The reconstructive procedure used the second toe and the anterolateral thigh flap in 5 patients, the second toe and the scapular flap in 2, the big toe wraparound flap and the anterolateral thigh flap in 3, and the big toe wrapround flap and the scapular flap in 1. The 2 independent free tissues were connected together by a vascular combination to form an assembly with 1 common vascular pedicle, which then was anastomosed to the selected vessels in the recipient hand. In this vascular series the dorsalis pedis artery and the greater saphenous vein served as the common vascular pedicle of the flap transfers and the radial artery and the cephalic vein provided the recipient vessels. The outcomes of the reconstructions were evaluated using the Michigan Hand Outcomes Questionnaire. RESULTS: The flaps survived completely in all patients except 1. In this patient a small area in the distal part of the transplanted anterolateral thigh flap became necrotic but healed after dressing changes without the need for further surgical intervention. A mean follow-up period of 3.6 years showed a mean increase of 4.3 cm in the width of the thumb-index web space and a considerable improvement in overall hand function was noted on the Michigan Hand Outcomes Questionnaire with effect sizes of greater than 3 (large effect) in all domains. CONCLUSIONS: Combined transplantation of the second toe or the big toe wraparound flap and a free skin flap is suitable to reconstruct a missing thumb and repair the associated skin defect in the adjacent thumb-index web space. We found good functional recovery and an acceptable appearance in this series of patients. Type of study/level of evidence: Therapeutic, Level IV. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic, Level IV.

Activities of Daily Living↗

PubMed2005

Exposure of phage T7 to simulated space environment: the effect of vacuum and UV-C radiation.

The experiment "Phage and Uracil Response" (PUR) will be accommodated in the EXPOSE facility of the International Space Station (ISS). Its objective is to examine and quantify the effect of specific space conditions on bacteriophage T7 and isolated T7 DNA thin films. In order to define the environmental and technical requirements of the EXPOSE, the samples were subjected to the Experiment Verification Test (EVT). During EVT the samples were exposed to selected space conditions: high vacuum (10(-4) to 10(-6) Pa) and UV-C radiation (254 nm) alone and in combination. Characteristic changes in the absorption spectrum, in the electrophoretic pattern of DNA/phage and the decrease of the amount of PCR products have been detected indicating the damage of isolated and intraphage T7 DNA. Intraphage DNA is more sensitive to simulated space parameters than isolated T7 DNA in thin layers as well. We obtained substantial evidence that DNA lesions accumulate throughout exposure, and the amount of damage depends on the thickness of the layers. According to our preliminary results, the damages by exposure to conditions of dehydration and UV irradiation are larger than the sum of vacuum alone, or radiation alone case, suggesting a synergistic action of space vacuum and UV radiation with DNA being the critical target.

Bacteriophage T7↗

PubMed2005

Charting epilepsy by searching for intelligence in network space with the help of evolving autonomous agents.

The problem of demarcating neural network space is formidable. A simple fully connected recurrent network of five units (binary activations, synaptic weight resolution of 10) has 3.2 *10(26) possible initial states. The problem increases drastically with scaling. Here we consider three complementary approaches to help direct the exploration to distinguish epileptic from healthy networks. [1] First, we perform a gross mapping of the space of five-unit continuous recurrent networks using randomized weights and initial activations. The majority of weight patterns (>70%) were found to result in neural assemblies exhibiting periodic limit-cycle oscillatory behavior. [2] Next we examine the activation space of non-periodic networks demonstrating that the emergence of paroxysmal activity does not require changes in connectivity. [3] The next challenge is to focus the search of network space to identify networks with more complex dynamics. Here we rely on a major available indicator critical to clinical assessment but largely ignored by epilepsy modelers, namely: behavioral states. To this end, we connected the above network layout to an external robot in which interactive states were evolved. The first random generation showed a distribution in line with approach [1]. That is, the predominate phenotypes were fixed-point or oscillatory with seizure-like motor output. As evolution progressed the profile changed markedly. Within 20 generations the entire population was able to navigate a simple environment with all individuals exhibiting multiply-stable behaviors with no cases of default locked limit-cycle oscillatory motor behavior. The resultant population may thus afford us a view of the architectural principles demarcating healthy biological networks from the pathological. The approach has an advantage over other epilepsy modeling techniques in providing a way to clarify whether observed dynamics or suggested therapies are pointing to computational viability or dead space.

Action Potentials↗

PubMed2005

Searching on patch networks using correlated random walks: space usage and optimal foraging predictions using Markov chain models.

We describe a novel representation of a discrete correlated random walk as the transition matrix of a Markov chain with the displacements as the states. Such a representation makes it possible to utilize results from the theory of absorbing Markov chains, to make biologically interesting predictions without having to resort to Monte Carlo simulations. Our motivation for constructing such a representation is to explore the relationship between the movement strategy of an animal searching for resources upon a network of patches, and its consequent utilization of space and foraging success. As an illustrative case study, we have determined the optimal movement strategy and the consequent usage of space for a central place forager utilizing a continuous movement space which is discretized as a hexagonal lattice. The optimal movement strategy determines the size of the optimal home range. In this example, the animal uses mnemokinesis, which is a sinuosity regulating mechanism, to return it to the central place. The movement strategy thus refers to the choice of the intrinsic path sinuosity and the strength of the mnemokinetic mechanism. Although the movement space has been discretized as a regular lattice in this example, the method can be readily applied to naturally compartmentalized movement spaces, such as forest canopy networks. This paper is thus an attempt at incorporating results from the theory of random walk-based animal movements into Foraging Theory.

Animals↗

PubMed2006

Medicine and the space odyssey.

Up to the mid-1960s, science and technology (including medicine) were generally regarded as exciting, beautiful and spiritually enthralling; and the space odyssey seemed a symbol of the optimistic future of humankind. The early seventies saw a growing disillusionment with space travel as part of a mood of cultural pessimism and anti-modernization - and this combined with a resurgence of therapeutic nihilism in medicine. But recent discussions of renewed space exploration and a Mars mission may be evidence of a changing zeitgeist, with Western culture moving towards a bolder and more optimistic attitude. The adventure of space travel, exploration and colonization could be seen as both a barometer of cultural optimism, and an enterprise which would feed-back into cultural optimism for many decades to come. Medical science could also be a beneficiary; since greater boldness and optimism would be likely to renew the goals of medicine to do positive good - as contrasted with the necessary, but relatively uninspiring, requirement to minimize risk and harm. In a modernizing society humankind needs to look outward as well as inward: we need a frontier, and we need to grow. A resurgent space odyssey may be the best way that this can be enacted.

Extraterrestrial Environment↗

PubMed2005

High b-value q-space diffusion MRI in myelin-deficient rat spinal cords.

In this study, we explore the effect of the lack of myelin on the diffusion characteristics and diffusion anisotropy obtained from high b-value q-space diffusion-weighted MRI (q-space DWI) in excised rat spinal cords. Twenty-one-day-old myelin-deficient (md) mutant (N=6) and control rats (N=6) were used in this study. The MRI protocol included multi-slice T(1), T(2), proton density (PD) MR images and high b-value q-space diffusion MRI measured perpendicular and parallel to the fibers of the spine. q-Space displacement and probability maps, in both directions, as well as displacement anisotropy maps, were computed from the diffusion data. At the end of the MRI protocol, representative spinal cords from both groups were subjected to electron microscopy (EM). The md spinal cords show different gray/white matter contrast in the T(1), T(2) and PD MR images as compared with controls. In addition, the mean displacement extracted from the high b-value q-space diffusion data was found to be dramatically higher in the white matter (WM) of the md spinal cords than the controls when diffusion was measured perpendicular and parallel to the fibers of the spine. However, interestingly, at the diffusion time used in the present study, the difference in the WM displacement anisotropies of the two groups was not found to be statistically significant. Myelin was found to have a pronounced effect on the diffusion characteristics of water in WM but less so on the diffusion anisotropy observed at the diffusion time used in the present study.

Animals↗

PubMed2006

MR image reconstruction of sparsely sampled 3D k-space data by projection-onto-convex sets.

In many rapid three-dimensional (3D) magnetic resonance (MR) imaging applications, such as when following a contrast bolus in the vasculature using a moving table technique, the desired k-space data cannot be fully acquired due to scan time limitations. One solution to this problem is to sparsely sample the data space. Typically, the central zone of k-space is fully sampled, but the peripheral zone is partially sampled. We have experimentally evaluated the application of the projection-onto-convex sets (POCS) and zero-filling (ZF) algorithms for the reconstruction of sparsely sampled 3D k-space data. Both a subjective assessment (by direct image visualization) and an objective analysis [using standard image quality parameters such as global and local performance error and signal-to-noise ratio (SNR)] were employed. Compared to ZF, the POCS algorithm was found to be a powerful and robust method for reconstructing images from sparsely sampled 3D k-space data, a practical strategy for greatly reducing scan time. The POCS algorithm reconstructed a faithful representation of the true image and improved image quality with regard to global and local performance error, with respect to the ZF images. SNR, however, was superior to ZF only when more than 20% of the data were sparsely sampled. POCS-based methods show potential for reconstructing fast 3D MR images obtained by sparse sampling.

Algorithms↗