Efficient and Unbiased Estimation of Population Size.

Population sizing from still aerial pictures is of wide applicability in ecological and social sciences. The problem is long standing because current automatic detection and counting algorithms are known to fail in most cases, and exhaustive manual counting is tedious, slow, difficult to verify and unfeasible for large populations. An alternative is to multiply population density with some reference area but, unfortunately, sampling details, handling of edge effects, etc.

Sampling theory and automated simulations for vertical sections, applied to human brain.

In recent years, there have been substantial developments in both magnetic resonance imaging techniques and automatic image analysis software. The purpose of this paper is to develop stereological image sampling theory (i.e.

Flowers and wedges for the stereology of particles.

Recently, a new decomposition has been found for the motion invariant density of straight lines in, with applications in stereology. The new principle, called the invariator, leads to new rotational formulae which express the surface area and the volume of a bounded subset (called a 'particle') in terms of an observable functional defined in an isotropically oriented section (called a pivotal section) through a fixed point (called the pivotal point). The results have been extended to intrinsic volumes of manifolds in general space forms.

Stereology of isolated objects with the invariator.

The invariator is a new stereological design to generate motion invariant test lines in three dimensions on an isotropic plane through a fixed point. The theory has been published recently. The purpose of this paper is to illustrate the application of the invariator on a group of rat brains to estimate brain volume and external surface area.

[Stereology as a tool to estimate brain volume and cortical atrophy in elders with dementia].

Introduction: stereology is a body of methods that allow unbiased and efficient estimation of geometric quantities defined in arbitrary physical structures. In particular, stereology is a valuable tool to assist neuroimaging in the estimation of morphometric parameters in the brain. Therefore, stereology may confer objectivity in the complementary and diagnostic evaluation of dementia by adding disease by adding quantitative data to clinical evaluation.

New variance expressions for systematic sampling: the filtering approach.

We present a collection of variance models for estimators obtained by geometric systematic sampling with test points, quadrats, and n-boxes in general, on a bounded domain in n-dimensional Euclidean space R(n), n = 1, 2, ...

A general variance predictor for Cavalieri slices.

A general variance predictor is presented for a Cavalieri design with slices of an arbitrary thickness t >or= 0. So far, prediction formulae have been available either for measurement functions with smoothness constant q = 0, 1, ..

A new stereological principle for test lines in three-dimensional space.

A new principle is presented to generate isotropic uniform random (IUR) test lines hitting a geometric structure in three-dimensional space (3D). The principle therefore concerns the estimation of surface area, volume, membrane thickness, etc., of arbitrary structures with piecewise smooth boundary.

Estimation of particle number by stereology: an update.

Sampling designs dictated by stereology have proven very useful in recent years to estimate in situ the total number of deposited particles, or of macrophages, in different lung compartments at the light microscopical level. The sampling methods are based on parallel slabs which are subsequently subsampled by disectors. The resulting number estimators are unbiased irrespective of tissue shrinkage or swelling, and they are readily applicable in other contexts (notably in neuroscience).

Precision of the fractionator from Cavalieri designs.

A popular procedure to predict the variance of the fractionator consists in splitting the initial collection of fragments into two subsets, in order to use the corresponding particle counts (or any other pertinent measure), in the calculation. The current formula does not account for local or 'nugget' errors inherent in the estimation of fragment contents, however. Moreover, it does not account for the fact that the contribution of the variability between fragments or slices should rapidly decrease as the sampling fraction increases.

Comparison of MR imaging against physical sectioning to estimate the volume of human cerebral compartments.

The purpose of this study was to compare magnetic resonance imaging (MRI) against physical sectioning techniques to estimate the volume of human cerebral hemisphere compartments (cortex, subcortex, and their union, called "total"). The volume of these compartments was estimated postmortem for six human subjects from MRI virtual sections and from physical sections using the Cavalieri design with point counting. Cursory paired t tests revealed no significant differences between the two methods for any of the three compartments considered, although P = 0.

Precision of circular systematic sampling.

In design stereology, many estimators require isotropic orientation of a test probe relative to the object in order to attain unbiasedness. In such cases, systematic sampling of orientations becomes imperative on grounds of efficiency and practical applicability. For instance, the planar nucleator and the vertical rotator imply systematic sampling on the circle, whereas the Buffon-Steinhaus method to estimate curve length in the plane, or the vertical designs to estimate surface area and curve length, imply systematic sampling on the semicircle.

Does lack of Cftr gene lead to developmental abnormalities in the lung?

Lung disease is the major cause of death in cystic fibrosis (CF), but the effect of gene mutation on the morphology of the main structural compartments of the lung is poorly understood. We show here, to our knowledge for the first time, a quantitative comparison of the fine pulmonary structures of cftr mutant versus non-cf mice. Pertinent volumes and surface areas were estimated in 10 homozygous cftrm1HGU mutants and 11 non-cf littermates by unbiased stereology at the light microscopic level.

New approximations for the variance in cavalieri sampling.

The theory of Cavalieri sampling - or systematic sampling along an axis - has received a recent impetus. The error variance may be represented by the sum of three components, namely the extension term, the 'Zitterbewegung', and higher order terms. The extension term can be estimated from the data, and it constitutes the standard variance approximation used so far.

Estimation of brain compartment volume from MR Cavalieri slices.

Purpose: Recent theory has been developed to estimate volume from a systematic sample of tissue slices of a given thickness and to predict the corresponding error. Our goal was to check the error prediction formulas by resampling and to determine the minimum number of MR slices required to estimate the volumes of the cerebrum and of the compartments of gray matter (GM) and white matter (WM) with prescribed errors.

Method: Our working data set comprised the GM and WM segmentations obtained from a paradigmatic high signal-to-noise ratio 3D spoiled GRASS MR volume data set for a single healthy human subject.

Application of the fractionator and vertical slices to estimate total capillary length in skeletal muscle.

A new stereological method is proposed which combines vertical slice projections with the fractionator to estimate the total capillary length in a skeletal muscle. The method was demonstrated on the soleus muscle of a Wistar rat. The implementation required capillary highlighting, tissue sampling, and data acquisition in the form of intersection counts between capillary projections and cycloid test lines.

Stereological assessment of the glial reaction to chronic deafferentation of the cochlear nuclei in the macaque monkey (Macaca fascicularis).

Neurectomy of the auditory nerve produces a massive deafferentation of the cochlear nuclei (CN) in the brainstem. Degenerating primary afferents are removed in the acute phase, and this is followed by a synaptic reorganization in the CN. As part of an ongoing study on the effect and applicability of auditory brain implants in the CN of Macaca fascicularis monkeys, we studied the chronic response of astrocytes in the CN to bilateral deafferentation of the VIIIth cranial nerve.

Anxiogenic-like effects and reduced stereological counting of immunolabelled 5-hydroxytryptamine6 receptors in rat nucleus accumbens by antisense oligonucleotides.

The physiological role of 5-hydroxytryptamine6 receptors in the central nervous system has not yet been elucidated. The high affinity of various psychotropic drugs for 5-hydroxytryptamine6 receptors has led to the suggestion that this receptor type may be a novel target in neuropsychiatry. We have found that continuous intracerebroventricular administration of a 5-hydroxytryptamine6 receptor antisense oligonucleotide, but not of a missense oligonucleotide, produced an anxiogenic-like response in rats using two different models of anxiety, the social interaction test and the elevated plus-maze.

Precision of Cavalieri sections and slices with local errors.

Cavalieri sections--and more recently Cavalieri slices, especially in combination with non-invasive scanning--are widely used to estimate volumes. Physical Cavalieri slices are also increasingly used to estimate neuron numbers via the optical fractionator. In either case, the prediction of the error variance is important to assess optimal sample sizes.

Comparison of the phagocytosis of two types of cyclosporin (SDZ OXL 400 and SDZ IMM 125) by alveolar macrophages from hamsters.

The aim of this study was to compare two types of cyclosporin (Cs) particles, SDZ OXL 400 and SDZ IMM 125, the latter being more hydrophilic, to understand their uptake by airway macrophages. Alveolar macrophages (AM), harvested by bronchoalveolar lavage (BAL) of hamster lungs, were cultured with two different doses (0.1 mg and 0.

Influence of ovariectomy on the canine striated external urethral sphincter (M. urethralis): a stereological analysis of slow and fast twitch fibres.

Slow and fast twitch fibres were stereologically analysed in the morphologically defined and most strongly developed ventral and ventrolateral region of the external urethral sphincter (M. urethralis) using five sexually intact anestrous and five ovariectomized nulliparous beagles. The estimated mean total cross-sectional area of the investigated part of the muscle consisted of 4.

Hippocampal volume and neuronal number in Ts65Dn mice: a murine model of Down syndrome.

Ts65Dn mouse displays a partial triplication of chromosome 16 and is adopted as a model for Down syndrome (DS). It is known that Ts65Dn mice present memory deficiencies. In order to gain insight into the cause of these deficiencies, we studied the possibility of changes in volumes and neuronal numbers in different regions of the hippocampus (dentate gyrus, CA3, CA2 and CA1) in trisomic mice as compared to control littermates using stereological methods.

Comparison of the rate of phagocytosis of orthorhombic cyclosporine A (CsA) and latex particles by alveolar macrophages from hamsters.

The aim of this study was to develop an in vitro model to estimate the clearance of pulmonary administered cyclosporine A (CsA). To do this we estimated the volume of CsA particles phagocytosed by alveolar macrophages (AM) lavaged from hamsters. AM were cultured with CsA particles at two doses of particles (0.

Analysis of cardiac function by MRI and stereology.

Design-based stereology and phase contrast magnetic resonance imaging (MRI) were combined to monitor changes in the volume of the four chambers of the human heart during the cardiac cycle. The data set consisted of 18 adjacent slices (or 'scanning levels') of 0.5 cm thickness, perpendicular to the long axis of the body, and encompassing the whole heart of a healthy volunteer.

Efficiency of airway macrophage recovery by bronchoalveolar lavage in hamsters: a stereological approach.

Macrophages play a central role in the defence of the respiratory tract against deposited particles. In addition to the well-studied alveolar macrophages, airway macrophages have been recognized as an important clearance factor. Bronchoalveolar lavage (BAL) has been used for functional and morphological investigations of macrophages in vitro, assuming that all macrophages are removed with equal probability from the lung surface.