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PubMed2000

Compliance of peripheral airways deduced from morphometry.

Insights into airway mechanics were sought by applying morphometric techniques to rabbit lungs fixed at several lung recoil pressures. Rabbits were treated with either nebulized carbachol followed by iv administration of carbachol or with saline solution (sham). The lungs were held at one of six values of positive end-expiratory pressure (PEEP; 10, 7, 4, 2, 0, and -4 cmH(2)O) while the animal was killed and formalin was circulated through the lungs. The lungs were removed and left in a bath of formalin for 24 h. Standard airway morphometric measurements were made on membranous bronchiole slices taken from representative blocks of tissue. Reductions in PEEP produced the expected reductions in lumen area in the carbachol-treated airways but not in the sham-treated airways for PEEP > 2 cmH(2)O. Sham-treated airways remained more open than expected until they collapsed into an oval shape at PEEPs between 4 and 2 cmH(2)O. The carbachol-treated airways exhibited this behavior at PEEP = -4 cmH(2)O. The smallest airways, which had relatively thicker walls, collapsed less than larger airways. We postulate that this behavior implies that peribronchial stress is greater than lumen pressure on collapse into the oval shape. Resistance to buckling increases with the thickness-to-radius ratio of the airway wall, which explains why the smallest airways are the most open. The development of epithelial folds appeared to follow the theoretical prediction of a previous study (Lambert RK, Codd SL, Alley MR, and Pack RJ. J Appl Physiol 77: 1206-1216, 1994).

Animals↗
PubMed2006

Evaluation of emphysema severity and progression in a rabbit model: comparison of hyperpolarized 3He and 129Xe diffusion MRI with lung morphometry.

The apparent diffusion coefficients (ADCs) of hyperpolarized (3)He and (129)Xe gases were measured in the lungs of rabbits with elastase-induced emphysema and correlated against the mean chord length from lung histology. In vivo measurements were performed at baseline and 2, 4, 6, and 8 wk after instillation of elastase (mild and moderate emphysema groups) or saline (control group). ADCs were determined from acquisitions that used two b values. To investigate the effect of b value on the results, b-value pairs of 0 and 1.6 s/cm(2) and 0 and 4.0 s/cm(2) were used for (3)He, and b-value pairs of 0 and 5.0 s/cm(2) and 0 and 10.0 s/cm(2) were used for (129)Xe. At 8 wk after instillation, the rabbits were euthanized, and the lungs were analyzed histologically and morphometrically. ADCs for the rabbits in the control group did not change significantly from baseline to week 8, whereas ADCs for the rabbits in the emphysema groups increased significantly (P < 0.05) for all gas and b-value combinations except (129)Xe with the b-value pair of 0 and 5.0 s/cm(2). The largest percent change in mean ADC from baseline to week 8 (15.3%) occurred with (3)He and the b-value pair of 0 and 1.6 s/cm(2) for rabbits in the moderate emphysema group. ADCs (all b values) were strongly correlated (r = 0.62-0.80, P < 0.001) with mean chord lengths from histology. These results further support the ability of diffusion-weighted MRI with hyperpolarized gases to detect regional and global structural changes of emphysema within the lung.

Animals↗
PubMed2001

Neck muscles in the rhesus monkey. I. Muscle morphometry and histochemistry.

Morphometric methods were used to describe the musculotendinous lengths, fascicle lengths, pennation angles, and cross-sectional areas of neck muscles in adult Macaca mulatta monkeys. Additionally, muscles were frozen, sectioned, and stained for ATPase activity to determine fiber-type composition. Individual rhesus muscles were found to vary widely in their degree of similarity to feline and human muscles studied previously. Suboccipital muscles and muscles supplied by the spinal accessory nerve were most similar to human homologs, whereas most other muscles exhibited architectural specializations. Many neck muscles were architecturally complex, with multiple attachments and internal aponeuroses or tendinous inscriptions that affected the determination of their cross-sectional areas. All muscles were composed of a mixture of type I, IIa, and IIb fiber types the relative proportions of which varied. Typically, head-turning muscles had lower proportions of type II (fast) fibers than homologous feline muscles, whereas extensor muscles contained higher proportions of type II fibers. The physical and histochemical specializations described here are known to have a direct bearing on functional properties, such as force-developing capacity and fatigue-resistance. These specializations must be recognized if muscles are to be modeled accurately or studied electrophysiologically.

Adenosine Triphosphatases↗
PubMed1999

Primary unit for statistical analysis in morphometry: patient or cell?

In a series of 16 oxyphilic follicular neoplasms of the thyroid (8 adenomas and 8 carcinomas), three different approaches for the analysis of morphometric data were evaluated. It was shown that the statistical design of morphometric studies is by nature nested due to subsampling of cells within each patient. Therefore, the most appropriate analysis would be to account for this hierarchical structure. However, related statistical methods are not at present well established, especially as far as classification rules are concerned. Therefore, the nested design is converted into the simple factorial one by considering only one kind of statistical unit - either patients or cells. The results of the study presented indicate that ignoring the patient as unit of analysis leads to a substantial error in statistical output, regardless of the particular procedure applied. Moreover, the size of the error can be neither diminished nor controlled. Choosing patients as primary units assures accurate results and also has an advantage of gaining some additional information by calculating several distributional estimates in each patient. However, this approach often requires a reduction of dimensions and, furthermore, is not encouraged in certain fields of quantitative cytology. Advantages and disadvantages of all approaches have been summarized and practical recommendations for their use have been worked out.

Adenocarcinoma, Follicular↗
PubMed2003

Use of nuclear morphometry characteristics to distinguish between normal and abnormal cervical glandular histologies.

This is a methodological study exploring the use of quantitative histopathology applied to the cervix to discriminate between normal and cancerous (consisting of adenocarcinoma and adenocarcinoma in situ) tissue samples. The goal is classifying tissue samples, which are populations of cells, from measurements on the cells. Our method uses one particular feature, the IODs-Index, to create a tissue level feature. The specific goal of this study is to find a threshold for the IODs-Index that is used to create the tissue level feature. The main statistical tool is Receiver Operating Characteristic (ROC) curve analysis. When applied to the data, our method achieved promising results with good estimated sensitivity and specificity for our data set. The optimal threshold for the IODs-Index was found to be 2.12.

Adenocarcinoma↗
PubMed1998

Comparative morphometry of mammalian central auditory systems: variation in nuclei and form of the ascending system.

The volumes of the ten largest subcortical auditory nuclei were measured individually in a sample of 53 mammals, including 16 Australian and four American marsupials. The nuclear sizes relative to the total of subcortical auditory tissue were normalized and then analyzed individually for statistically reliable deviations. The overall form of the entire system of ten nuclei and two nuclear sub-systems (cochlear nuclei, superior olives) were also analyzed for similarities and notable deviations among the animals. The results show that the absolute size of the auditory system varies more than 139-fold among the 53 mammals (with moles the smallest and humans the largest). Log auditory system volume and log brain weight are closely correlated (r = 0.903, p < 0.0001). Bats, kangaroo rats, marmosa opossums, and Norway rats have the largest auditory systems relative to their brain size, while humans have the smallest by far. The other primates also have auditory system/brain size ratios smaller than the sample average, suggesting that the condition in humans is one result of an expansion of non-auditory brain parts rather than a reduction of the auditory system over geological time. The relative sizes of the ten nuclei are well ordered, with the inferior colliculus the largest nucleus by far and medical superior olive the smallest. Because the size of the superior olives, collectively, is reliably related to the size of anteroventral cochlear nucleus (r = 0.744, p < 0.001), and not to the size of dorsal cochlear nucleus, the interconnectivity of the subcortical auditory system is probably a factor in the size of the nuclei. In its overall form, the subcortical auditory system is highly similar among mammals, with an average correlation across nuclei of 0.923. This high value means that the overall form of the system has been relatively stable over geological time. The animals with least deviation from the average form are ring-tailed possums, bandicoots, and yellow-bellied gliders, all marsupials. Those with the most unusual forms are mice, bats, and kangaroo rats, all placentals.

Animals↗
PubMed2000

Capillarity, fibre types and fibre morphometry in different sampling sites across and along the tibialis anterior muscle of the rat.

Capillarity, fibre types, fibre cross-sectional areas and perimeters were studied along and across the rat tibialis anterior muscle. The muscle was sectioned at three different levels (proximal, equatorial and distal) choosing five sampling fields for measurements at each level (from anterior to posterior and lateral to medial zones). Significant differences were found in the percentage of fibre types and capillarity between different fields of the same muscle section. Slow oxidative fibres were confined to the posterior muscle zone with a maximum of 3.7%. The posterior fields also had a greater percentage of fast oxidative glycolytic fibres at proximal (72.3%) and equatorial (61.3%) levels, but a lower value at the distal level (44.8%) and lower capillary density counts in total cross-section means (758 vs. 1,069 capillaries/mm(2) in equatorial and 1,035 capillaries/mm(2) at proximal levels). The uneven distribution of both fast fibre types and the different degrees of capillarisation along the muscle are statistically significant and may be due to different biomechanical performances along the rat tibialis anterior. Fibre size was significantly larger at the distal level, but no morphometric differences were found across the section of the same level. At the distal level, the mean total fibre area of fast glycolytic fibres (5,130 microm(2)) and fast oxidative glycolytic fibres (2,493 microm(2)) contrasted with values at the proximal (fast glycolytic: 4,070 microm(2), fast oxidative glycolytic: 1,970 microm(2)) and equatorial (fast glycolytic: 3,535 microm(2), fast oxidative glycolytic: 1,714 microm(2)) levels. The differences along and across the muscle show the need to design a standardised procedure for sample location when performing comparative studies of morphofunctional adaptive changes in skeletal muscle. A significant difference between individuals (animals) in all parameters was evident and should be taken into consideration when analysing the variability: the factor 'animal' should be considered in multiway ANOVAs, especially when low sample sizes are used.

Analysis of Variance↗
PubMedDate not supplied

Morphometry of axon cytoskeleton at internodal regions of rat sciatic nerve during aging.

BACKGROUND: Nerve endings undergo a lifespan morphofunctional modulation which is reported to be markedly impaired with aging. Neurone structural remodelling is in charge of processes occurring in the nerve cell soma, however the axonal transportation of organelles and molecules by cytoskeletal elements plays a very important role in the morphological rearrangements taking place at peripheral compartments. OBJECTIVE: To assess the involvement of axonal ultrastructure in the reported age-related decline of slow axoplasm flow mechanisms, we carried out a morphometric study of axon cytoskeleton in aging. METHODS: Female Wistar rats (3, 12 and 30 months of age) were anesthetized and perfused with saline followed by a fixation solution (glutaraldehyde 5% + formalin 2% in 0.1 cacodylate buffer pH 7.4). The excised sciatic nerves were processed according to conventional electron microsopic procedures. Axons sectioned perpendicularly to their longitudinal axis at the internodal region (mean axoplasm area: 18.25-26.5 microm(2)) were sampled by a systematic random procedure. The overall number of neurofilaments (No.Nfs) and microtubules (No.Mts) per total axoplasm area analysed, the numeric density (number/microm(2) of axoplasm area) of neurofilaments (NaNfs) and microtubules (NaMts), the myelin thickness, the number of myelin lamellae and the R proportion [No. Nfs/(No.Nfs + No.Mts)] were the parameters measured by computer-assisted semiautomatic methods. RESULTS: No.Nfs, NaNfs, myelin thickness and the number of myelin lamellae did not change between 12 and 30 months of age, while a significant increase of these parameters was found in a comparison with younger rats. No.Mts and NaMts were significantly increased at 12 vs. 3 as well as at 30 vs. 12 months of age, respectively. R proportion did not show any difference due to age. CONCLUSIONS: The present findings support that the dynamic condition of the axonal cytoskeleton appears to be preserved at a high extent in aging. Thus, the intra-axonal defective spacing of cytoskeletal elements (e.g. neurofilaments), rather than their number, is proposed to contribute to the decline of the slow axonal transport of organelles and molecules reported in aging.

Actin Cytoskeleton↗
PubMed1988

Accommodation motor neurons in the foveate teleost Paralabrax clathratus: horseradish peroxidase labeling and axonal morphometry, with comparisons to other ciliary nerve components.

Although much is known about the optics and mechanism of ocular accommodation in teleost fishes, there is to date no description of the neurons innervating the muscle of accommodation, the lens retractor. I have identified accommodation motor neurons in the kelp bass, Paralabrax clathratus, by backfilling the lens retractor nerve (a branch of the short ciliary nerve) with the retrograde tracer horseradish peroxidase. These neurons comprise a subpopulation of relatively large unipolar neurons in the ciliary ganglion. Backfilling either of the remaining ciliary nerve branches (which innervate mainly cornea and iris) labels smaller cells in the ciliary ganglion as well as sensory neurons in the profundus ganglion and sympathetic neurons in the trigeminal sympathetic ganglion. No labeled cells were found in the brain in any of these experiments. I have also examined the lens retractor nerve and the corneal-iridal branch of the short ciliary nerve by electron microscopy. Counts of axons in these nerves from animals of different sizes suggest postembryonic growth of axon number in the corneal-iridal branch but not in the lens retractor nerve. The latter comprises approximately 100 myelinated and a few unmyelinated axons. Its diameter spectrum shows a preponderance of large-diameter axons, but the myelin sheaths are unusually thin (mean axon diameter: 7.5 micron; mean ratio axon diameter/fiber diameter: g = 0.81 for 830-gram animal). The results indicate that kelp bass accommodation motor neurons lie primarily if not entirely within the ciliary ganglion. Some of their axons are the largest in the short ciliary nerve, but their sheath thicknesses are apparently not optimal with respect to conduction velocity.

Accommodation, Ocular↗
PubMed1990

Regional brain morphometry and lissencephaly in the Sirenia.

Neuroanatomical structure was examined in the brains of West Indian manatees (Trichechus manatus) using computer-based morphometric methods. Although manatees have a small relative brain size, volume estimates of the major brain regions indicate that the telencephalon comprises 71% of total brain volume and is 90% cerebral cortex. These values are comparable to those seen among a diversity of taxa having large relative brain size, including many primates. Manatee brains also exhibit well-defined cortical lamination. The measured gyration index (an index of cortical folding) was 1.06, representing a highly lissencephalic condition. These findings demonstrate that small relative brain size and lissencephaly do not constrain the elaboration of internal brain structures. The marked lissencephalic condition is unusual for brains of this absolute size range, and may be related to the thickness of the cortical gray matter and underlying white matter.

Animals↗
PubMed1990

Morphometry and function of islet cells after different forms of drainage at pancreatic transplantation in rats.

The survival of endocrine cells of the islets is crucial for a successful transplantation of the pancreas in the treatment of diabetes mellitus. In the present investigation, we compared the effect of four techniques of whole pancreas transplantation in rats on the endocrine cells of islets of Langerhans. Impairment of the endocrine function of the pancreas with a decrease in the k value was seen after 6 months in the group with duct ligation, and after 12 months in the groups with latex and ethibloc occlusion. An open pancreatic duct maintains a more stable endocrine function than in duct-ligated or occluded grafts. Fasting plasma insulin and somatostatin were elevated in transplanted rats. Whichever method of transplantation we chose, the cell ratio remained unchanged compared with the control group, even after 12 months. Therefore, only intact islet architecture enables a normal endocrine pancreatic function.

Animals↗
PubMed1982

Light microscopic morphometry of the lung of 19 avian species.

The lungs of 107 birds of 19 different species from seven orders were fixed in situ. The mean volumes of both fixed lungs together ranged from 0.15 to 95.31 cm3. Histological sections of one lung from each bird were analyzed by point counting with a Zeiss integrating eyepiece to determine the volume densities and thence the absolute volumes of the main functional components of the lung. The mean volume density of the exchange tissue was highest in the 11 passeriform species (53.5%) and lowest in the 2 charadriiform species (34.6%); that for all of the 8 non-passeriform species was 42.6%. The possible significance of these variations in relation to the differing oxygen requirements of these groups of birds is discussed. The parabronchi showed minor variations in the degree of development of the interparabronchial septa, atria, interatrial septa, and atrial muscles. The diameter of the parabronchi (including the mantle of exchange tissue) ranged from about 0.34 mm in the passeriform species to about 0.63 mm in Anser anser; the lumen of the parabronchus accounted for about half of this diameter. Body weight an lung volume were strongly correlated (0.995); the allometric function relating lung volume to body weight was 29.5 w0.988.

Animal Population Groups↗
PubMed1985

Morphometry of monocytes of human blood.

Morphometric methods have been used to analyse the ultrastructural characteristics of human blood monocytes in 20 normal adults. Data were obtained relating to whole cell, nucleus and mitochondria and, using a method not previously applied to blood cells, for the distribution of heterochromatin and euchromatin. The results provide a normal baseline against which monocyte changes in disease can be assessed.

Adolescent↗
PubMed1987

Morphometry and ultrastructure of the squirrel monkey (Saimiri sciureus) vestibular nerve.

Vestibular nerves of squirrel monkeys (Saimiri sciureus) embedded in plastics and epoxies were examined with light microscopy (LM) and transmission electron microscopy (TEM), and computerized measures were obtained and analyzed statistically. An average of 12,412 perikarya and 12,005 myelinated nerve fibers was obtained. Approximately 0.7% of the perikarya appeared unmyelinated under LM. About 500 unmyelinated fibers were counted. The cross-sectional area of 1,864 perikarya was 200-650 micron 2. The cross-sectional area of 1,346 nerve fibers was 3-11 micron 2 for the axoplasm and 11-12 micron 2 for the myelin sheath of the same fiber. Myelin thickness was directly proportional to the axoplasm cross-sectional area of the nerve fibers. The cross-sectional area of central axons and peripheral dendrites differed significantly (p less than 0.001). The initial segments of peripheral dendrites were usually smaller, but longer than the initial segments of the central axons. Both initial segments increased in diameter after the first node of Ranvier. Schmidt-Lantermann incisures were more abundant in thick and heavily myelinated fibers than in thin and lightly myelinated fibers. Larger perikarya usually had larger fibers and vice versa, within the first 100-200 micron from the first node of Ranvier. No major ultrastructural differences were found between myelinated and unmyelinated perikarya, except at the hillock region. The Nissl substance was preferentially located in the peripheral cytoplasm.

Animals↗
PubMed1987

Morphometry of eosinophils in human blood.

Ultrastructural characteristics of human blood eosinophils have been analysed by morphometric methods in 18 healthy adults. Data were obtained relating to whole cell, nucleus, mitochondria and specific granules. No significant differences were found between the eosinophils of the 9 male and 9 female subjects. The results provide normal values against which changes in eosinophils in disease states may be assessed.

Adult↗
PubMed1995

Alcohol effects on paraventricular hypothalamic nucleus morphometry.

The morphometric effects of postnatal exposure to alcohol on the neurons of the paraventricular hypothalamic nucleus (PVN) have been studied in four different topographic subdivisions of the nucleus: rostral, intermediate medial, intermediate lateral and caudal. Male mice were exposed to alcohol during lactation and after weaning by addition of 20% of ethanol to the drinking water that was first ingested by the mother and thereafter by the experimental animals themselves. Animals were sacrificed at the 25th, 35th, 45th, 55th and 100th postnatal day. Nuclear sizes of the PVN neurons (Perimeter, area and maximum diameter) were determined in both control and experimental alcohol-treated groups. The shape of these neuronal nuclei was also determined and compared. PVN responds globally to alcohol exposure, showing a decrease in the neuronal nuclear sizes in the four studied PVN subdivisions of the alcohol-treated mice at the 35th and 45th and 100th day. We suggest that these decreases could be related to changes in gonadal hormone levels induced by alcohol exposure and/or disturbances of brain neurotransmitter and neuropeptide metabolism caused by ethanol.

Animals↗
PubMed1996

Morphometry of pineal synaptic ribbon profile numbers after cytochalasin D treatment.

Synaptic ribbons (SRs) are electron-dense, plate-shaped synaptic organelles, to which electron-lucent synaptic vesicles (SVs) are attached by tiny stalks. In the mammalian pineal gland SRs are dynamic organelles, waxing and warning in number under different physiological and experimental conditions. The way in which SRs are formed, or catabolized, is not known. Since it has been suggested that actin may be part of SRs, in the present study the effect of the actin-disrupting drug cytochalasin D (CD, 1 microgram/ml, for 4 h) was examined in cultured guinea pig and rat pineal glands. The glands were preincubated for 48 h so that intra-pineal sympathetic nerve fibres degenerate and no longer release noradrenaline which may distort the results. CD had no effect on SR profile numbers in guinea pigs, but decreased them in rats (p > 0.05). The nonsignificant depressive effect of CD in rats was verified in a second experiment. To clarify the issue, acutely cultured rat pineal glands were treated with CD for 4 h, without effect. The results taken together suggest to us that CD has no major effect on pineal SR profile numbers, but that in rats preincubation for 48 h makes them vulnerable to catabolic processes. In all the experiments, the electron-dense plate of the SRs was qualitatively unaffected. However, the SVs were often larger and more irregular in shape and the stalks linking the SVs with the SRs were less frequently seen in CD-treated glands. In guinea pig pineals, in which SRs frequently lie in groups and parallel to each other, neither the distance between neighboring SRs nor the thickness of individual SRs were affected by CD. It is concluded that actin is not a major component of the SRs and the connecting stalks.

Animals↗