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PubMed2001

Spatial and temporal analysis of left ventricular filling flow propagation in hypertensive patients before and after regression of myocardial hypertrophy with alacepril therapy.

The purpose of this study was to assess the clinical significance of spatial and temporal analysis of left ventricular (LV) filling-flow propagation using color M-mode Doppler echocardiography before and after regression of LV hypertrophy in patients with hypertension. Seven patients with hypertensive LV hypertrophy were studied. Echocardiographic and Doppler examinations were performed both before and after 6 months administration of alacepril. LV mass index (LVMI), LV flow propagation velocity (FPV), and the maximal early transmitral flow velocity (E) were measured. LVMI, FPV, and FPV/E ratio were compared to before and after administration of alacepril. In addition, the correlation between LVMI and FPV/E ratio was evaluated. Results showed that LVMI was significantly decreased (P < 0.05) and the FPV/E ratio was significantly increased (P < 0.05) after treatment with alacepril. There was no significant change in FPV. In addition, there was a significant negative correlation between LVMI and the FPV/E ratio (r = -0.662, P < 0.001). The present study indicates that the FPV/E ratio could be a useful noninvasive parameter to assess the diastolic dysfunction associated with LV hypertrophy in patients with hypertension.

Aged↗

PubMed1992

[Spatial and quantitative analysis of the QRS and T waves by Frank-lead orthogonal electrocardiography in normal children. Comparative study in an early and late cord-clamping groups in newborns].

We studied a spatial and quantitative analysis of QRS and T waves by Frank-lead orthogonal electrocardiography (afterwards; ECG) in 50 cases of normal newborns, 30 cases of infants, 50 cases of adults, and also the variation in age was investigated. In the newborns, the comparative study was made serially, longitudinally in 21 infants with an early clamping of the cord and 29 infants with a late clamping of the cord. The results are mainly as follows. 1) The parameters reflecting the cardiac electromotive force of the right ventricle such as Sx, Qz and Sx+Qz decreased with aging. 2) Rx, i.e., the maximum leftward projection of QRS vector increased until the children, probably because the left ventricle was dominant in their growth and development and in the increased amount of work. A subsequent reduced value in the adults was considered to be mainly due to an increase of the distance between the heart and electrode by the increase in the thorax, particularly the transverse diameter and due to the growth in subcutaneous fat and muscle. 3) The values of Rx/Sx increased with aging. Rx and Sx in the adults were less than those in the children, but Rx/Sx was larger than that of Rx because Sx was less than Rx. 4) Age-related changes of Tz was most characteristic and was negative up to several days after birth. T vector was in forward direction and then turned positive (in backward). This was greatest at the period of the infants. Subsequently, it turned negative in the childhood, and extent was maximum in the adults.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed2002

Parallel distributed processing neuroimaging in the Stroop task using spatially filtered magnetoencephalography analysis.

Parallel distributed processing neuroimaging in the Stroop color word interference task in five healthy subjects was studied. The total reaction time was set at 650 ms with a time window of 200 ms in steps of 50 ms. Spatially filtered magnetoencephalography analysis, as used in synthetic aperture magnetometry, was used. Neural activation began in the left posterior parietal-occipital area (150-250 ms post-stimulus), followed by the right prefrontal polar area (250-350 ms), the left dorsolateral prefrontal cortex (250-400 ms), and the mid- to lower- primary motor area (350-400 ms). Successive and temporally overlapping activation of various cortical regions were successfully estimated within a short 200 ms time interval, contrary to previous positron emission tomography and fMRI studies.

Adult↗

PubMedDate not supplied

[Possibility of biocompatibility of fullerene C60 with oligopeptides using a comparative analysis of their spatial form].

It was proposed to elucidate the mechanism of unique biological biocompatibility of carbon materials used for making endoprostheses for medicinal practice. For this purpose, a method of comparing the geometry of individual globular and fibrillar proteins and carbon structures (fullerenes) was advanced, and a comparative analysis of the spatial structure of fullerene C60 and the amino acid sequences of 286 proteins was made. Based on a high degree of similarity in the positions of atoms of the polypeptide chains of proteins and peptides and the corresponding atoms of fullerene and of other structural parameters revealed by the comparison of the spatial structures using mathematical simulation, the phenomenon of biological compatibility was interpreted as an "insertion" of fullerenes into the structure of protein molecules in place of structurally similar amino acid sequences, i.e., as a "prosthetics" at the molecular level. It is proposed that fullerenes can "simulate" structurally similar short peptides in biological processes. It was shown that noncarbon biogenic atoms play a large role in the formation of specific structure of protein molecules.

Amino Acid Sequence↗

PubMed2004

Quantification of human atherosclerotic plaques using spatially enhanced cluster analysis of multicontrast-weighted magnetic resonance images.

One of the current limitations of magnetic resonance imaging (MRI) is the lack of an objective method to classify plaque components. Here we present a cluster analysis technique that can objectively quantify and classify MR images of atherosclerotic plaques. We obtained three-dimensional (3D) images from 12 human coronary artery specimens on a 9.4T imaging system using multicontrast-weighted fast spin-echo (T1-, proton density-, and T2-weighted) imaging with an isotropic voxel size of 39 micro. Spatially enhanced cluster analysis (SECA) was performed on multicontrast MR images, and the resulting segmentation was evaluated against histological tracings. To visualize the overall structure of plaques, the MR images were rendered in 3D. The specimens exhibited lesions of American Heart Association (AHA) plaque classification types I-VI. Both MR images and histological sections were independently reviewed, categorized, and compared. Overall, the classification obtained from the cluster-analyzed MR and histopathology images showed very good agreement for all AHA types (92%, Cohen's kappa = 0.89, P < 0.0001). All plaque types were identified and quantified by SECA with a high degree of correlation between cluster-analyzed MR and manually traced histopathology data. MRI combined with SECA provides an objective method for atherosclerotic plaque component characterization and quantification.

Analysis of Variance↗

PubMed1979

An analysis of the spatial distribution of attenuation values in computed tomographic scans of liver and spleen.

An autocorrelation analysis of the attenuation values in computed tomographic scans has been performed for a total of 35 normal and eighteen cirrhotic patients. The results confirm preliminary observations on a smaller sample which suggested that this technique may be used to separate normal and cirrhotic livers. The noise structure in a region within the spleen was also examined and found to change in the presence of cirrhosis.

Humans↗

PubMed1988

A quantitative analysis of the spatial relationships of grouped microcalcifications demonstrated on xeromammography in benign and malignant breast disease.

The mammograms of 444 patients who had a breast biopsy leading to a definitive histological diagnosis were reviewed. In 21 cases (4.7%) grouped microcalcifications were identified as the only mammographic abnormality. These groups of microcalcifications were analysed to determine whether there was any quantitative difference between benign and malignant lesions with respect to a shape parameter of the group, the spatial frequency of the particles and neighbour-to-neighbour relationships of the particles. This analysis did not reveal any significant difference between the spatial relationships of the grouped microcalcifications found in benign and malignant breast disease.

Biopsy↗

PubMed1999

[Geographic differences of bronchopulmonary cancer mortality in France and spatial scales of analysis: significance of scale change in health geography].

BACKGROUND: It is important to choose a valid spatial scale to study health differences in a geographical perspective. Many scales can be valid and a combination is required to understand the spatial distribution of a given health problem. Geographic distribution of lung cancer was studied in France using different scales to illustrate the importance of changing scales in health geography. METHODS: Standardized rates (direct method) for lung cancer were calculated for the period 1988-92 and mapped at different scales. RESULTS: Original spatial structure was observed for each scale. This proved that different interactions occur at each scale between environmental and social factors. Changing the scale allowed a better understanding of variations in the spatial distribution of lung cancer. CONCLUSIONS: The validity of a regional scale to study health geographical distributions is questioned. Changing the scale would allow proposing action to improve health promotion.

Bronchial Neoplasms↗

PubMed1996

A new approach for evaluation of left ventricular diastolic function: spatial and temporal analysis of left ventricular filling flow propagation by color M-mode Doppler echocardiography.

OBJECTIVES: To evaluate left ventricular diastolic function and differentiate the pseudonormalized transmitral flow pattern from the normal pattern, the propagation of left ventricular early filling flow was assessed quantitatively using color M-mode Doppler echocardiography. BACKGROUND: Because the propagation of left ventricular early filling flow is disturbed in the left ventricle with impaired relaxation, quantification of such alterations should provide useful indexes for the evaluation of left ventricular diastolic function. METHODS: Study subjects were classified into three groups according to the ratio of early to late transmitral flow velocity (E/A ratio) and left ventricular ejection fraction: 29 subjects with an ejection fraction > or = 60% (control group); 34 with an ejection fraction < 60% and E/A ratio < 1 (group I); and 25 with ejection fraction < 60% and E/A ratio > or = 1 (group II). The propagation of peak early filling flow was visualized by changing the first aliasing limit of the color Doppler signals. The rate of propagation of peak early filling flow velocity was defined as the distance/time ratio between two sampling points: the point of the maximal velocity around the mitral orifice and the point in the mid-left ventricle at which the velocity decreased to 70% of its initial value. High fidelity manometer-tipped measurement was performed in 40 randomly selected subjects. RESULTS: The rate of propagation decreased in groups I and II compared with that in the control group (33.8 +/- 13.8 [mean +/- SD] and 30.0 +/- 8.6 vs. 74.3 +/- 17.4 cm/s, p < 0.001, respectively) and correlated inversely with the time constant of left ventricular isovolumetric relaxation and the minimal first derivative of left ventricular pressure (peak negative dP/dt) (r = 0.82 and r = 0.72, respectively). CONCLUSIONS: Spatial and temporal analysis of filling flow propagation by color M-mode Doppler echocardiography was free of pseudonormalization and correlated well with the invasive variables of left ventricular relaxation.

Blood Flow Velocity↗

PubMed1997

A comparison of spatial prediction techniques for an exploratory analysis of human cortical motor representations.

We compare the use of two-dimensional Laplacian smoothing splines and median polish kriging for an exploratory analysis of spatial data sets. Splines were developed originally for modelling a process with determinstic mean structure, while median polish kriging was developed for predicting a spatial random process. We review the fundamentals of both methods, including smoothing parameter selection for splines and variogram estimation and solving the kriging equations for median polish kriging. We demonstrate application of the methods on maps of muscle representations on the human motor cortex (cortical maps). After applying both methods to 20 cortical maps (left and right hemispheres on each of 10 subjects), we compare the fitted surfaces on the basis of predictive ability, aesthetic appeal, and ease of computation.

Analysis of Variance↗

PubMed2003

Fourier fringe analysis with improved spatial resolution.

The spatial resolution of the phase image derived from the interferogram by Fourier fringe analysis is limited by the necessity to isolate a first order in the Fourier plane. By use of the two complementary outputs of the interferometer, it is possible to eliminate the zero order and thus to improve the spatial resolution by a factor of approximately 2. The theory of this improvement is presented and confirmed experimentally.

Journal Article↗

PubMed1988

Spatial and temporal analysis of disease occurrence for detection of clustering.

Data on disease occurrence often consist of the number of cases recorded in a set of regions during each of several time periods. In this paper a method of analysis of such data is proposed which allows one to distinguish and test for spatial clustering, temporal clustering, and space-time clustering of cases. Departures of case numbers from expectation are partitioned into region and time period main effects and region-by-time interactions. Spatial and temporal relationships among regions and time periods are incorporated by pooling estimates over neighborhoods. In addition to providing tests for clustering, the analysis identifies the contributions to clustering made by individual neighborhoods. Data on Creutzfeldt-Jakob disease in France are used to illustrate the approach.

Biometry↗

PubMed1995

Incoherent spatial impulse response in variable-cross-section photoreceptors and frequency-domain analysis.

The spatial impulse response of a single variable-cross-section photoreceptor has been characterized assuming the incoming radiation to be an initial field propagating under confinement conditions inside the receptor. By application of Fourier analysis the total transfer function is determined. Both the outer and the inner segments are characterized as low-pass filters. The dependence of the transfer function on the modal parameter is analyzed.

Fourier Analysis↗

PubMed2006

Using geographical information systems and spatial microsimulation for the analysis of health inequalities.

The paper presents a spatial microsimulation approach to the analysis of health inequalities. A dynamic spatial microsimulation model of Britain, under development at the Universities of Leeds and Sheffield, uses data from the censuses of 1971, 1981 and 1991 and the British Household Panel Survey to simulate urban and regional populations in Britain. Geographical information systems and spatial microsimulation are used for the analysis of health inequalities in British regions in a 30 year simulation. The interdependencies between socio-economic characteristics and health variables such as limiting long-term illness are discussed. One of the innovative features of the model is the estimation of variables such as household income at the small area level, which can then be used to classify individuals. The health situation of different simulated individuals in different areas is investigated and the role of socio-economic characteristics in determining health is evaluated.

Adult↗

PubMed2004

Spatial and temporal analysis of the distribution of hantavirus pulmonary syndrome in Buenos Aires Province, and its relation to rodent distribution, agricultural and demographic variables.

We studied the spatial and temporal distribution of Hantavirus Pulmonary Syndrome (HPS) cases from 1998 to 2001 in the Buenos Aires Province, Argentina. HPS is a severe viral disease whose natural reservoir are rodents of the subfamily Sigmodontinae (Muridae) and which occurs in many countries of South and North America. We considered two spatial arrangements: cells of 18.5 x 18.5 km(2); and departments, the political subdivisions of the province, as spatial units. We tested the departure from a Poisson distribution of the number of cases per cell and per month with the Variance/Mean index, while the interaction between spatial and temporal clustering was tested by means of the Knox and Mantel tests. We constructed probability maps in which the HPS rates per department were considered Poisson variates according to population, area and the product of population and area. We analysed the relation between rodent distribution, environmental and demographic variables and HPS cases conducting preliminary univariate analysis from which we selected variables to enter in general linearized models. We found that both the spatial and temporal distribution of cases is strongly aggregated. The spatiotemporal interaction appears to be related to a strong seasonality and the existence of particular ecological conditions rather than epidemic transmission of the disease. The main explanatory variables for the distribution of HPS cases among the departments of the Buenos Aires Province were human population, the distribution of the rodent Oxymycterus rufus and evapotranspiration. The last two variables are probably indicators of favourable ecological conditions for the reservoirs, which encompass other variables not taken into account in this study.

Agriculture↗

PubMed2000

Difference spatial distribution function analysis of aqueous solutions. III. Hydration structures of alcohol and ether solutions having straight chain and branched alkyl groups.

Spatial distribution functions (SDFs), gOO(x,y,z) and gOH(x,y,z), obtained from Monte Carlo simulations at 298 K were applied to characterize the anisotropic structure of infinitely dilute aqueous solutions of alcohols and ethers having straight chain and branched alkyl groups. In spite of the different size and shape of the hydrophobic groups, the spatial orientation of the hydrogen-bonded water molecules was found to be of linear type with a triple layer structure in the hydrogen acceptor (HA) region and a double layer structure in the hydrogen donor (HD) region. The volumes and the coordination number (CN) in the HA region were essentially identical for all alcohol and ether solutions, but the volumes for the isopropyl alcohol (IPA) and isopropyl methyl ether (IPE) solutions were greater than those for the other solutions. In the hydrophobic hydration (HH) region, these values increased with increasing size and shape of hydrophobic groups, except in the case of IPA and IPE solutions. These results indicated that the hydration structures around the isopropyl group in alcohol and ether solutions differed from those in other solutions. From the results of the difference SDF (DSDF), AgOO(x,y,z), between SDFs gOO(x,y,z) for the two states, it was apparent that the distribution of hydration water molecules in the HA region for ether solution was characterized by the increase of the distribution in the direction of lone pair electrons on the oxygen atom of the solute molecule with increasing hydrophobicity.

Alcohols↗

PubMed2025

Multi-omics analysis reveals distinct spatial compartmentalization of lung repair niches in pediatric ARDS.

BACKGROUND: Pediatric acute respiratory distress syndrome (PARDS), often triggered by viral infections, is a life-threatening condition. Despite its severity, children demonstrate significantly better survival rates and superior lung repair compared to adults. However, the mechanisms underlying this age-specific advantage remain incompletely understood. PATIENTS AND METHODS: We conducted a pilot multi-omics study of influenza-associated PARDS integrating single-cell RNA sequencing (scRNA-seq) of pediatric lung tissue and bronchoalveolar lavage fluid (BALF), spatial transcriptomics, and plasma proteomics. Analyses were harmonized with the Human Lung Cell Atlas (HLCA) reference, reanalysis of public pediatric PARDS airway scRNA-seq, and contextual comparisons to adult lethal COVID-19 lung. RESULTS: Tissue scRNA-seq and spatial data indicated outcome-linked divergence in PARDS. Survivor showed spatially restricted repair with preserved alveolar type II (AT2) cells, AT2-to-alveolar type I (AT1) differentiation signatures, and higher KRT17, whereas fatal case and adults exhibited diffuse immune activation with pro-fibrotic and pro-apoptotic signaling. In BALF, KRT17-positive airway stress–repair epithelial cells (hillock-like) increased from the acute to recovery phase, and plasma proteomics showed higher circulating KRT17 in survivors. HLCA-based label transfer strengthened cell-type definitions and enabled pediatric–adult comparisons suggesting biological and developmental differences; the adult lethal COVID-19 atlas provided a benchmark with attenuated epithelial repair and prominent collagen CTHRC1-pathologic fibroblasts. Fibroblast programs were regionally compartmentalized, with injury-enriched CTHRC1+ states versus alveolar fibroblasts in preserved areas, and showed stronger injury–homeostasis anti-correlation in fatalities. Myeloid remodeling included BALF transitions from FCN1-high inflammatory states toward FABP4-positive resident-like states, consistent with public pediatric datasets showing reduced inflammatory and interferon-stimulated gene (ISG) modules and severity-linked increases in aged neutrophils. CONCLUSIONS: This pilot multi-omics case series outlines putative pediatric lung repair niches in influenza-associated PARDS. KRT17-positive transitional epithelium, preserved AT2 differentiation, and restoration of resident-like macrophages may align with recovery, whereas diffuse immune activation and CTHRC1-enriched fibroblast programs may accompany worse outcomes. HLCA-guided annotations and adult benchmarks indicate possible age-related differences, warranting validation in larger multi-center cohorts.

Humans↗

PubMed1985

Emergence and characterization of sex differences in spatial ability: a meta-analysis.

Sex differences in spatial ability are widely acknowledged, yet considerable dispute surrounds the magnitude, nature, and age of first occurrence of these differences. This article focuses on 3 questions about sex differences in spatial ability: What is the magnitude of sex differences in spatial ability? On which aspects of spatial ability are sex differences found? and When, in the life span, are sex differences in spatial ability first detected? Implications for clarifying the linkage between sex differences in spatial ability and other differences between males and females are discussed. We use meta-analysis, a method for synthesizing empirical studies, to investigate these questions. Results of the meta-analysis suggest that sex differences arise on some types of spatial ability but not others, that large sex differences are found only on measures of mental rotation, that smaller sex differences are found on measures of spatial perception, and that, when sex differences are found, they can be detected across the life span.

Adolescent↗