Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Size”

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 109 records · Page 6Linked to original sources
PubMedDate not supplied

Breast size as risk factor for tumor size at diagnosis.

BACKGROUND: A prospective study was conducted to determine whether patients with larger breasts show larger tumors. MATERIALS AND METHODS: 123 patients with primary breast cancer were evaluated (median follow-up 36 months). Breast size was determined as a reflection of cup size. RESULTS: Cup size correlated with tumor diameter at diagnosis (p = 0.0038). On average, cup sizes were larger in postmenopausal than in premenopausal women (p = 0.0011), however, postmenopausal women did not show larger tumors than premenopausal. There was a significant positive correlation between body mass index, body weight and breast size (p < 0.0001). The mode of tumor detection (self vs. not self) was independent of breast size. No correlation was found between breast size and the patient's height, duration of breast feeding, smoking behavior or amount of alcohol consumption, hormone replacement therapy or use of oral contraceptives, number of involved lymph nodes or DFS and OS. CONCLUSION: Patients with larger breasts showed larger tumors. The mode of tumor detection is independent of breast size.

Adult↗
PubMed1975

Cusp size, sexual dimorphism, and heritability of cusp size in twins.

Overall measures of mandibular molars reflect the combined size contributions of the component cusps and ridges. Until now, the size hierarchy of primary and permanent mandibular molar cusps remained unclear. This paper utilizes the relative plane surface areas (basal area dimensions) of the individual molar cusps, as assays of cusp size to demonstrate cusp size variations within populations, antimere cuspal variations, sexual dimorphism, and, the heritability of cusp size. Duplicate dental casts from 199 pairs of like-sexed twins provide the raw dats. Defined anatomic landmarks on the occlusal surfaces were reduced to X-Y rectangular coordinates prior to the computation of the basal areas dimensions. The results establish a cusp size hierarchy specific for molar type, i.e., five-cusped molars with a distal fovea and distal marginal ridge (5fd), five-cusped molars without a distal fovea and without a distal marginal ridge (5o), and four-cusped molars (4c). Sexual dimorphism in cusp size is apparent in 5fd molar cusped but not in 5o molar cusps. However, males have a significantly higher frequency of 5fd molars. Females have a higher frequency of smaller 5o and 4c molars which have fewer crown components. Moreover, female 5o molars have cusps as large as or larger than 5o male molor cusps. Right-side-left-side differences exist between antimere cusps based on relatively low correlations. The mirroring of molor types occurs infrequently. When observed, most intrapair differences for cusp size, using F-ratios, indicate a low component of hereditary variability.

Dentition↗
PubMed1998

Optical Sizing of Ultrafine Metallic Particles: Retrieval of Particle Size Distribution from Spectral Extinction Measurements.

The inverse problem of optical sizing of ultrafine metallic particles from the spectral extinction measurements in the visible range is investigated. Solving the inverse problem becomes possible due to the strong size effect which in the framework of classical electrodynamics can be described by the dependence of complex refractive index on the particle size. It is shown that the size effect leads to the considerable increase of information content of spectral extinction data with respect to desired size composition of the particles. This makes it possible to retrieve the size distribution of ultrafine metallic particles with reasonably high accuracy, including the Rayleigh size region. The analysis is performed mainly within the framework of numerical tests by the typical example of ultrafine silver particles in a gelatin matrix. The results in retrieving of size distribution from experimentally measured extinction spectra are also presented. Calculations of spectral extinction coefficient are made by means of Mie theory. In so doing, the dielectric function of particles is modified by using the electron's mean free path limitation model. Copyright 1998 Academic Press.

Journal Article↗
PubMed2005

Muzzle size, paranasal swelling size and body mass in Mandrillus leucophaeus.

The drill (Mandrillus leucophaeus), a forest-living Old World monkey, is highly sexually dimorphic, with males exhibiting extreme secondary sexual characteristics, including growth of paranasal swellings on the muzzle. In this study, the size of the secondary bone that forms the paranasal swellings on the muzzles of drills was assessed in relation to body mass proxies. The relationship between the overall size of the muzzle and surrogate measures of body mass was also examined. In female drills, muzzle breadth was positively correlated with two proxies of overall body mass, greatest skull length and upper M1 area. However, there was no such correlation in males. Paranasal swellings in males also appeared to have no significant relationship to body mass proxies. This suggests that secondary bone growth on the muzzles of male drills is independent of overall body size. Furthermore, this secondary bone appears to be vermiculate, probably developing rapidly and in an irregular manner, with no correlation in the sizes of paranasal swelling height and breadth. However, various paranasal swelling dimensions were related to the size of the muzzle. It is suggested that the growth of the paranasal swellings and possibly the muzzle could be influenced by androgen production and reflect testes size and sperm motility. The size and appearance of the paranasal swellings may thus be an indicator of reproductive quality both to potential mates and male competitors. Further work is required to investigate the importance of the paranasal swellings as secondary sexual characteristics in Mandrillus and the relationship between body size and secondary sexual characteristics. Attention should also be paid to the mechanisms and trajectories of facial growth in Mandrillus.

Animals↗
PubMed1989

Stability of cell size and nucleolar size in tangle-bearing neurons of the hippocampus in Alzheimer's disease.

Samples of 14 brains of autopsied patients suffering from dementia of the Alzheimer type were examined. In Congo red-hemalum stained 14-microns-thick sections of the hippocampus 15 tangle-bearing and 25-30 unaffected nerve cells of area CA1 per case were measured for cell size and nucleolar size utilizing an interactive image processing unit. In affected cells tangle size was measured too. There was no significant difference in neuron size and nucleolar size between affected and unaffected cells. In tangle-bearing cells nucleolar size and cell size were not correlated with tangle size. Since nucleolar volume can serve as an indicator of RNA synthesis of a cell, tangles themselves seem not to disturb nerve cell metabolism.

Aged↗
PubMed1994

Stability of cell size and nucleolar size in Lewy body containing neurons of substantia nigra in Parkinson's disease.

Samples of 9 brains of autopsied patients suffering from Parkinson's disease were examined. In H & E stained 20 microns thick sections of substantia nigra 10 Lewy body containing and 20 unaffected pigmented nerve cells of substantia nigra per case were measured for size of the perikarya and nucleolar size utilizing an interactive image processing unit. In affected cells the size of Lewy bodies was measured too. There was no significant difference in the size of the perikarya and nucleolar size between affected and unaffected cells. In Lewy body bearing cells nucleolar size was not correlated with the size of the Lewy bodies. There was a significant negative correlation between nucleolar size of substantia nigra neurons and the duration of the disease. Since nucleolar volume can serve as indicator of RNA synthesis of a cell, Lewy bodies do not seem to disturb nerve cell metabolism.

Aged↗
PubMed1993

Changes in oscillometric pulse amplitude envelope with cuff size: implications for blood pressure measurement criteria and cuff size selection.

Oscillometric blood pressures are derived from the amplitude envelope of oscillometric pulses generated in an occlusive cuff during cuff inflation or deflation; one factor which will affect the characteristics of these pulses is the size of the cuff bladder. Because limiting values are stipulated in recommendations and standards for bladder sizes, there is a wide variety of acceptable cuff sizes for any particular application. An experimental and theoretical study was undertaken to show the dependence of oscillometric blood pressures on bladder size. Actual cuff-arm compliance data were obtained from two subjects for two cuffs of different bladder size. Theoretical analysis was then applied to the data to predict the effects of different bladder sizes on the characteristics of the pulses. The results show that cuff-arm compliance and bladder size interact to affect the pulse amplitude and hence oscillometric blood pressure determination. These results suggest that blood pressures obtained using the oscillometric method may vary depending on cuff size, and in particular that replacement cuffs for oscillometric non-invasive blood pressure monitors should be chosen carefully.

Blood Pressure Determination↗
PubMed1990

Effect of intravenous streptokinase on the relation between initial ST-predicted size and final QRS-estimated size of acute myocardial infarcts.

Thrombolytic therapy has been documented to reduce acute myocardial infarct size. The previously established relation between initial ST segment elevation and final electrocardiographic (ECG) myocardial infarct size in patients without coronary reperfusion might therefore be altered by thrombolytic therapy. The effect of intravenous streptokinase on this relation was therefore studied in 73 patients with initial acute myocardial infarction who had participated in the Second International Study of Infarct Survival (ISIS-2). Patients who received streptokinase were considered as one group and patients who did not receive streptokinase as a control group. Final myocardial infarct size, which was estimated from the QRS score, was predicted from the admission standard ECG by previously developed formulas based on ST segment elevation. In the 40 control patients there was no change from ST-predicted to final QRS-estimated infarct size (median 17.7% versus 18.3%; p = NS). In the 33 patients in the streptokinase group, there was a highly significant decrease from predicted to final myocardial infarct size (median 21.9% versus 16.2%; p less than 0.0002). This decrease was found for both anterior (median 23.7% versus 19.5%; p less than 0.03) and inferior (median 21.9% versus 12.0%; p = 0.001) infarct locations. Multiple regression analysis adjusting for differences in predicted infarct size confirmed the significance of streptokinase on the difference in infarct size (p = 0.006). Based on the variability of the percent change from predicted to final infarct size in the control group, a threshold decrease greater than or equal to 20% is required for identification of salvage.(ABSTRACT TRUNCATED AT 250 WORDS)

Aspirin↗
PubMedDate not supplied

Density-induced plant size reduction and size inequalities in ethylene-sensing and ethylene-insensitive tobacco.

Plant competition for light is a commonly occurring phenomenon in natural and agricultural vegetations. It is typically size-asymmetric, meaning that slightly larger individuals receive a disproportionate share of the light, leaving a limited amount of light for the initially smaller individuals. As a result, size inequalities of such stands increase with competition intensity. A plant's ability to respond morphologically to the presence of neighbour plants with enhanced shoot elongation, the so-called shade avoidance response, acts against the development of size inequalities. This has been shown experimentally with transgenic plants that cannot sense neighbours and, therefore, show no shade avoidance responses. Stands of such transgenic plants showed a much stronger development of size inequalities at high plant densities than did wild type (WT) stands. However, the transgenic plants used in these experiments displayed severely hampered growth rates and virtually no response to neighbours. In order to more precisely study the impact of this phenotypic plasticity on size inequality development, experiments required plants that have normal growth rates and reduced, but not absent, shade avoidance responses. We made use of an ethylene-insensitive, transgenic tobacco genotype (Tetr) that has wild type growth rates and moderately reduced shade avoidance responses to neighbours. Here, we show that the development of size inequalities in monocultures of these plants is not affected unambiguously different from wild type monocultures. Plots of Tetr plants developed higher inequalities for stem length than did WT, but monocultures of the two genotypes had identical CV (Coefficient of Variance) values for shoot biomass that increased with plant density. Therefore, even though reduced shade avoidance capacities led to the expected higher size inequalities for stem length, this does not necessarily lead to increased size inequalities for shoot biomass.

Analysis of Variance↗
PubMed2004

Habitat size, recruitment, and longevity as factors limiting population size in stage-structured species.

Surprisingly little research has evaluated how habitat size may limit the population size of species that use different habitats at different stages of their lives. Here we develop simple discrete-time models to describe the population dynamics of species that use separate juvenile and adult habitats. Analytic solutions, model simulations, and elasticity and sensitivity analyses show that adult abundance is only limited by the size of the juvenile habitat when both adult habitat size and recruitment are much larger than juvenile habitat size. Juvenile habitat plays a marginally greater role in limiting population size for species with closed populations, where recruitment is proportional to adult abundance, versus open populations. Because adult populations often accumulate pulses of juveniles, adult habitat size can strongly limit population size over a broad range of parameter values, an effect that increases as the longevity of a species increases. Limited empirical research from a range of taxa supports these model predictions, although few studies were designed to actually test the limiting role of juvenile versus adult habitat. Future research must carefully evaluate whether and how processes at the juvenile stage affect adult abundance, and conservation efforts may be able to use this model to evaluate the cost-effectiveness, vis-a-vis increasing adult abundance, of time and money allocated to protecting juvenile habitats.

Animals↗
PubMed2005

The leaf size-twig size spectrum of temperate woody species along an altitudinal gradient: an invariant allometric scaling relationship.

BACKGROUND AND AIMS: The leaf size-twig size spectrum is one of the leading dimensions of plant ecological variation, and now it is under development. The purpose of this study was to test whether the relationship between leaf size and twig size is isometric or allometric, and to examine the relationship between plant allometric growth and life history strategies in the spectrum. METHODS: Leaf and stem characters-including leaf and stem mass, total leaf area, individual leaf area, stem cross-sectional area, leaf number and stem length-at the twig level for 59 woody species were investigated along an altitudinal gradient on Changbaishan Mountain in the temperate zone of China. The environmental gradient ranges from temperate broad-leaved mixed forest at low altitude, to conifer forest at middle altitude, and to sub-alpine birch forest at high altitude. The scaling relationships between stem cross-sectional area and stem mass, stem mass and leaf mass, and leaf mass and leaf area at the twig level were simultaneously determined. KEY RESULTS: Twig cross-sectional area was found to have invariant allometric scaling relationships with the stem mass, leaf mass, total leaf area and individual leaf area, all with common slopes being significantly larger than 1, for three altitudinal-zoned vegetation types under investigation. However, leaf mass was found to be isometrically related to stem mass and leaf area along the environmental gradient. Based on the predictions of previous models, the exponent value of the relationship between twig cross-sectional area and total leaf area can be inferred to be 1.5, which falls between the confidence intervals of the relationship at each altitude, and between the confidence intervals of the common slope value (1.17-1.56) of this study. This invariant scaling relationship is assumed to result from the fractural network and/or developmental constraints of plants. The allometric constants (y-intercepts) of the relationships between the stem cross-sectional area and leaf area (both total leaf area and individual leaf area) were found to decrease significantly along the altitudinal gradient. This suggests that the species would support less leaf area at a given twig cross-sectional area with increasing environmental stress. CONCLUSIONS: This study demonstrated that plants respond to the environmental gradient by changing the y-intercepts of the relationship between leaf size-twig size, while keeping the exponent value of the allometric relationship as an invariant constant. The allometric growth in the twig size-leaf size spectrum is related to many other components of plant life history strategy, including the well established life history trade-off between efficiency and safety in the hydraulic transport of water.

Acclimatization↗
PubMed1995

Age and body size effects on blood meal size and multiple blood feeding by Aedes aegypti (Diptera: Culicidae).

Ten-day-old, parous Aedes aegypti (L.) had a higher threshold of blood meal size for the inhibition of continued host-seeking than did 5 d-old, nulliparous females of the same size. Older females of a smaller-bodied cohort had a higher threshold of blood meal size for the initiation of egg development than did younger females. In contrast, older larger-sized females had a lower blood meal-size threshold for egg development. The blood of paired avian hosts was marked with rubidium and cesium to study the effect of age and body size on the frequency of multiple blood feeding. Chronologically old females had a higher frequency of multiple blood feeding than younger females. In the laboratory, the frequency of multiple blood feeding among larger-sized females was higher than among small-sized females.

Aedes↗
PubMed1982

X-ray tube focal spot sizes: comprehensive studies of their measurement and effect of measured size in angiography.

Thirty-two focal spot sizes of four x-ray tubes were measured by the pinhole, star pattern, slit, and root-mean-square (RMS) methods under various exposure conditions. The modulation transfer functions (MTFs) and line spread functions (LSFs) were also determined. The star pattern focal spot sizes agreed with the effective sizes calculated from the frequencies at the first minimum of the MTF within 0.04 mm for large focal spots and within 0.01 mm for small focal spots. The focal spot size determined by the slit method was approximately equal to the width of the LSF at the cutoff level of 0.15 +/- 0.06 of the peak value. The RMS method provided the best correlation between the measured focal spot sizes and the corresponding image distributions of blood vessels. The pinhole and slit methods tended to overestimate the focal spot size, but the star pattern method tended to underestimate it. For approximately 90% of the focal spots, the average of the star and slit (or pinhole) focal spot sizes agreed with the RMS focal spot size within +/- 0.1 mm.

Angiography↗
PubMed1987

Airway size is related to sex but not lung size in normal adults.

Within individuals, lung size as assessed by total lung capacity (TLC) or vital capacity (VC) appears to be unrelated to airway size as assessed physiologically by maximum expiratory flows (MEF). Green et al. (J. Appl. Physiol. 37: 67-74, 1974) coined the term dysanapsis (unequal growth) to express this apparent interindividual discrepancy between parenchymal and airway size. We have reexamined this discrepancy using both physiological and anatomic indexes of airway size. Airway area by acoustic reflectance (AAAR), peak expiratory flow rates (PEFR), MEF, and lung volumes were measured in 26 male and 28 female healthy nonsmoking adults. The effect of sex on these indexes of large airway size was significant when assessed in a subset of males and females whose TLC's were matched (5.0-6.5 liters). Within this subset, male AAAR was 2.79 +/- 0.45 cm2, whereas female AAAR was 1.99 +/- 0.67 cm2 (P less than 0.01). Male's PEFR and MEF after 25% of VC had been expired (MEF25) were 23% greater than those of females within this subset (P less than 0.05). For the entire group of subjects, once these sex-related differences had been accounted for, AAAR was not significantly related to TLC, whereas PEFR and MEF25 remained at best weakly related to TLC. We conclude that tracheal areas in males are significantly larger than those of females even after controlling for TLC and that after controlling for sex-related differences, tracheal size in adults is unrelated to lung size across a broad range of lung sizes.

Adult↗
PubMed2003

NMDA receptor blockade in the superior colliculus increases receptive field size without altering velocity and size tuning.

Neonatal brain injury triggers compensatory processes that can be adaptive or detrimental, but little is known about the mechanisms of compensation or how they might affect the response properties of neurons within the injured region. We have studied this issue in a rodent model. Partial ablation of the hamster superior colliculus (SC) at birth results in a compressed but complete visual field map in the remaining SC and a compensatory conservation of receptive field (RF) size and stimulus velocity and size tuning. The circuit underlying stimulus tuning in this system or its preservation after brain lesions is not known. Our previous work has shown that N-methyl-d-aspartate (NMDA) receptors are necessary for the development and conservation of RF size after partial SC ablation. In this study, we examined whether NMDA receptor function is also necessary for the development and conservation of stimulus velocity and size tuning. We found that velocity and size tuning were unaffected by chronic postnatal blockade of NMDA receptors and the resulting increases in RF size. Thus NMDA receptors in the SC are not necessary for the development of stimulus velocity and size tuning or in the compensatory maintenance of these properties following brain damage. These results suggest that stimulus velocity and size tuning may arise in the retina or from NMDA receptor-independent circuitry intrinsic to SC. The lack of conflict between NMDA receptor activity-dependent and -independent processes may allow conservation of some RF properties while others change during injury-induced or evolutionary changes in afferent/target convergence.

2-Amino-5-phosphonovalerate↗
PubMed2001

The influence of genetic and environmental factors in estimations of current body size, desired body size, and body dissatisfaction.

The objective was to investigate the genetic epidemiology of figural stimuli. Standard figural stimuli were available from 5,325 complete twin pairs: 1,751 (32.9%) were monozygotic females, 1,068 (20.1%) were dizygotic females, 752 (14.1%) were monozygotic males, 495 (9.3%) were dizygotic males, and 1,259 (23.6%) were dizygotic male-female pairs. Univariate twin analyses were used to examine the influences on the individual variation in current body size and ideal body size. These data were analysed separately for men and women in each of five age groups. A factorial analysis of variance, with polychoric correlations between twin pairs as the dependent variable, and age, sex, zygosity, and the three interaction terms (age x sex, age x zygosity, sex x zygosity) as independent variables, was used to examine trends across the whole data set. Results showed genetic influences had the largest impact on the individual variation in current body size measures, whereas non-shared environmental influences were associated with the majority of individual variation in ideal body size. There was a significant main effect of zygosity (heritability) in predicting polychoric correlations for current body size and body dissatisfaction. There was a significant main effect of gender and zygosity in predicting ideal body size, with a gender x zygosity interaction. In common with BMI, heritability is important in influencing the estimation of current body size. Selection of desired body size for both men and women is more strongly influenced by environmental factors.

Adolescent↗
PubMed2001

[Estimation of size of the uncuffed endotracheal tube for pediatric cardiac anesthesia--Cole's formula cannot estimate the appropriate tube size].

We evaluated the validity of Cole's formula (tube size = 0.25 x age + 4) for the estimation of uncuffed endotracheal tube size, and devised new formula with a statistical method on the basis of the ages of 217 pediatric patients with congenital heart disease. The sizes of the tubes actually used for these patients were 0.5 mm or larger than those estimated by Cole's formula in 29% of patients with congenital heart disease. Only one patient with cyanotic heart disease required a tube that was more than 0.5 mm smaller than that estimated by Cole's formula. The regression formula representing the relationship between the tube size and age was "tube size = 0.316 x age + 4.135". In conclusion, tube size estimated by Cole's formula tends to be smaller than practically appropriate tube size for pediatric cardiac anesthesia, and therefore we suggest new formula to estimate the tube size.

Age Factors↗
PubMed1985

The relationship between airway size and lung size.

To investigate the association between airway size and lung size, the relationships between upstream conductance (reflecting airway size) and vital capacity (reflecting lung size) was explored in 22 male and 15 female subjects free of respiratory disease. The size-corrected maximal flows and size-corrected upstream conductances were not significantly correlated with vital capacity in males or females suggesting an association between lung and airway size. This was corroborated by other data from the literature analysed in a similar manner. The data further suggested that for a given lung size, the airways of females were on average as large or larger than those of males.

Adult↗