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  • 11
    Electronic Resource
    Electronic Resource
    Small intestinal morphology in experimental diabetic rats: a stereological study on the effects of an aldose reductase inhibitor (ponalrestat) given with or without conventional insulin therapy (1989)
    Springer
    Diabetologia 32 (1989), S. 649-654 
    Details
    ISSN: 1432-0428
    Keywords: Diabetes mellitus ; insulin injection ; aldose reductase inhibitor ; small intestine ; villi ; crypts ; muscularis externa ; stereology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The gross and microscopical dimensions of small intestines from 12-week old streptozotocin-diabetic rats receiving no therapeutic intervention were compared with those from animals receiving insulin alone or in conjunction with the aldose reductase inhibitor, ponalrestat. Four regions along each intestine were analysed stereologically. Insulin had significant beneficial effects on body weight as well as on intestinal length, width, surface area and volume. In contrast, ponalrestat did not improve body weight deficits and was associated with crypt hypertrophy and a reduced villous surface/crypt volume ratio. There were interaction effects between insulin and ponalrestat for intestinal length and primary mucosal surface area. All groups displayed significant regional differences in surface area of primary mucosa and volume of muscularis externa. Only untreated diabetic rats failed to reveal regional variation in the surface area and volume of villi. Ratios of villous surface area/crypt volume varied from region-to-region in insulin-treated diabetic rats but not in other groups. The study fails to reveal any beneficial effect of aldose reductase inhibition on the changes in intestinal morphology seen in experimental diabetes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00274251
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  • 12
    Electronic Resource
    Electronic Resource
    Oxygen diffusive conductance in placentae from control and diabetic women (1993)
    Springer
    Diabetologia 36 (1993), S. 955-960 
    Details
    ISSN: 1432-0428
    Keywords: Placenta ; stereology ; oxygen diffusion ; diabetes mellitus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Random tissue sections of placentae from control and diabetic deliveries were analysed stereologically. The aim was to test whether or not adaptations in oxygen diffusive conductances occur to help compensate for fetal hypoxic stress in utero. Organs were from 34 control and 55 diabetic deliveries (39 from White's classes A, B, C and 16 from classes D, F/R) arranged in two major groups (ABC and DFR). Tissue samples were fixed in formalin and processed for wax histology. Stereological and physicochemical quantities were used to calculate the partial conductances of six tissue layers, viz. maternal erythrocytes and plasma, villous trophoblast, villous stroma, fetal plasma and fetal erythrocytes. From partial conductances and birthweights, total and specific conductances for each placenta were determined. No differences were detected between diabetic placentae in different classes (A, B, C, D, F/R). However, both the ABC and DFR groups of diabetic placentae had higher total diffusive conductances than control organs. The increase was in the order of 7–25% and persisted even when adjustments were made for apparent differences in birthweights. The principal contributors to these changes were the post-trophoblastic (fetally located) tissue layers. These findings suggest that the diabetic placenta adapts to facilitate the diffusion of oxygen across the placenta and, thereby, to assist the hypoxic fetus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02374479
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  • 13
    Electronic Resource
    Electronic Resource
    Microangiopathy in human diabetic neuropathy: relationship between capillary abnormalities and the severity of neuropathy (1989)
    Springer
    Diabetologia 32 (1989), S. 92-102 
    Details
    ISSN: 1432-0428
    Keywords: Diabetes ; neuropathy ; microangiopathy ; heterogeneity ; morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Clinical, electrophysiological and ultrastractural morphometric observations were made in 5 diabetic non-neuropathic patients, 5 diabetic patients with mild neuropathy and 11 diabetic patients with severe neuropathy. Capillary abnormalities were assessed in simultaneous nerve, muscle and skin biopsies and compared with results from 6 age-matched, non-diabetic control subjects. Nerve capillaries demonstrated markedly greater pathology than skin and muscle capillaries. Endoneurial capillary density was significantly reduced in severely neuropathic diabetic patients (p〈0.01) when compared with control subjects. Capillary basement membrane (p〈0.002), endothelial cell (p〈0.003) and total diffusion barrier (endothelial cell, pericyte, basement membrane) (p〈0.001) thickness were significantly increased, and oxygen diffusing capacity was significantly reduced (p〈0.001) in the nerves of patients with severe diabetic neuropathy when compared to control subjects. Endothelial cell profile number and luminal perimeter were significantly increased in asymptomatic (p〈0.01), (p〈0.05) and severely neuropathic (p〈0.001), (p〈0.05) diabetic patients respectively. However, endothelial cell outer perimeter, a measure of capillary size, showed no significant increase in diabetic patients when compared with control subjects. An association was observed between neurophysiological and neuropathological measures of neuropathic severity. There was no significant correlation between the duration of diabetes and HbA1 levels with capillary pathology or with neuropathic severity. Very few abnormalities of muscle and skin correlated with neuropathic severity. However, all measures of nerve capillary pathology correlated significantly with neurophysiological and neuropathological measures of neuropathic severity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00505180
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  • 14
    Electronic Resource
    Electronic Resource
    The mass and size of normal and activated macrophages—Studies with a scanning interferometer (1973)
    Springer
    Cellular and molecular life sciences 29 (1973), S. 80-81 
    Details
    ISSN: 1420-9071
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Résumé Les dimensions et la masse sèche de macrophages normaux et activés ont été mesurées en utilisant le «Vickers M86 scanning interferometer and integrating microdensimeter». Une analyse statistique a montré un rapport positif entre les deux paramètres descriptifs, ce qui infirme une suggestion précédente selon laquelle une augmentation des dimensions d'un macrophage est accompagnée d'une perte de densité cytoplasmique.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01913265
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  • 15
    Electronic Resource
    Electronic Resource
    Membrane interiorization by phagocytosing macrophages — an ultrastructural morphometric approach (1978)
    Springer
    Cellular and molecular life sciences 34 (1978), S. 1338-1339 
    Details
    ISSN: 1420-9071
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Stereological methods have been used to quantify selected membrane compartments of normal and activated rat peritoneal macrophages, before and after phagocytosis of latex beads. Despite being rounder, activated cells are more efficient phagocytes: 30 min after latex challenge they suffer a greater nett depletion of plasma membrane and sequester more and larger phagocytic vacuoles. However, phagocytosis of latex is not the major route of membrane interiorization.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01981458
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  • 16
    Electronic Resource
    Electronic Resource
    Photoreceptor number and outer segment disk membrane surface area in the retina of the rat: stereological data for whole organ and average photoreceptor cell (1997)
    Springer
    Journal of neurocytology 26 (1997), S. 53-61 
    Details
    ISSN: 1573-7381
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A random sampling scheme is employed to obtain stereological estimates of disk membrane surface area in the entire retina and in the average photoreceptor cell. The scheme involves the use of vertical sections with combined light and electron microscopy at several magnification levels. Left and right retinas from six albino animals were analysed. There were no significant lateral differences. On average, the retina had a volume of 16 mm3, thickness of 200 μm and surface area of 80 mm2 (representing about 56% of the external surface of the eyeball). Photoreceptor disk membranes within outer segments amplified total retinal surface by almost 1000-fold (final surface 770 cm2 per retina). The retina contained 3×107 photoreceptors (packing density 374 000 mm-2) with an average disk membrane surface area of 2600 μm2. Mean nuclear volume in photoreceptor cells was 59 μm3 and the coefficient of variation for the distribution of nuclear volumes was 57%. The data are consistent with an average of 700 disks per photoreceptor cell, a membrane area of 4 μm2 per disk and a convergence ratio of ∼260 photoreceptors per optic nerve fibre. The basic scheme could be modified for other species and for direct cell counts conducted on rods and cones separately.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018563409196
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  • 17
    Electronic Resource
    Electronic Resource
    Quantitative microscopical studies of the mouse peritoneal macrophage following stimulation in vivo (1973)
    Springer
    Cell & tissue research 140 (1973), S. 187-202 
    Details
    ISSN: 1432-0878
    Keywords: Macrophage ; Differentiation ; Triolein ; Stereology ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The results of an objective two- and three-dimensional analysis of the morphological features of normal and triolein-induced mouse peritoneal macrophages are reported. An “equivalent circle“ technique for resolving the effects of volume and surface area on volume-to-surface parameters is described. The method is a simple comparative one which does not require the actual determination of cell volume. Macrophage stimulation promoted increases in mean cell size, cytoplasmic granularity and volume-to-surface ratio. In addition, a reduction in nuclear volume-to-surface ratio accompanied in vivo stimulation. Nucleocytoplasmic ratio remained constant. The equivalent circle procedure showed that the increase in cellular volume-to-surface ratio was due largely to the increase in cell volume; the decrease in nuclear volume-to-surface ratio was primarily the result of a substantial increase in nuclear membrane surface area. Stereological estimations suggest that interiorized cell membrane (in the form of triolein-containing phagosomes) is replaced by newly reconstructed surface membrane.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00306694
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  • 18
    Electronic Resource
    Electronic Resource
    Ultrastructural morphometry of blastogenesis I: Transformation of small lymphocytes stimulated in vivo with dinitrochlorobenzene (1979)
    Springer
    Cell & tissue research 200 (1979), S. 495-509 
    Details
    ISSN: 1432-0878
    Keywords: T-lymphocytes ; Blast cells ; Lymph node ; Electron microscopy ; Stereology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Changes in the volumes and surfaces of subcellular compartments of unstimulated small lymphocytes and immunoblasts in mouse axillary lymph nodes have been established using stereological techniques. Blast transformation was induced in vivo with dinitrochlorobenzene (DNCB). Cell samples were obtained by random sampling regimes applied at light and electron microscopic levels. From electron micrographs the volume densities of euchromatin, heterochromatin, nucleoli, mitochondria, Golgi apparatus and rough endoplasmic reticulum were determined. Cell surface/volume ratios were also computed. By estimating mean nuclear volumes using light microscopy, it was possible to calculate absolute compartmental volumes and to evaluate the plasma membrane surface areas of average cells. Transformation in this model was characterized by a considerable cellular hypertrophy and a substantial increase in plasmalemma surface. Hypertrophy was the consequence of increases in the volumes of all measured intracellular compartments, notably euchromatin and “residual cytoplasm” (including ground cytoplasm and free ribosomes). These changes are discussed in the context of the altered metabolic status of cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234859
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  • 19
    Electronic Resource
    Electronic Resource
    How to count synapses unbiasedly and efficiently at the ultrastructural level: proposal for a standard sampling and counting protocol (1996)
    Springer
    Journal of neurocytology 25 (1996), S. 793-804 
    Details
    ISSN: 1573-7381
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary After almost 40 years, there is still no concensus on criteria for identifying different types of synapse seen in electron microscopical thin sections or on methods for counting them unbiasedly in 3D. This review proposes a procedure which meets these aims and could be adopted as a standard best-practice sampling and counting convention. It deals exclusively with unbiased stereological methods for counting particles in 3D space because these are efficient and applicable to arbitrary particles regardless of their size, shape and orientation. Methods based on individual sections are excluded becausearbitrary particles cannot be counted unbiasedly with such sections. Model-based methods (e.g. treating synaptic membrane densities as circular disks) are excluded because they are not unbiased in general and now have limited (mainly historical) interest only. For unbiased counting, the absolute minimum requirement is apair of parallel sections (disector). The following protocol is recommended for future studies on synapse number: (1) use para(membrane) densities as synaptic counting units, (2) do not qualify definition of the counting unit by reference to a minimum number of synaptic vesicle profiles, (3) sample and count synapses unbiasedly using the disector, and (4) in preference convert number per volume into absolute number or, if this is not possible, estimate a synapse-to-neuron ratio.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02284842
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  • 20
    Electronic Resource
    Electronic Resource
    A review of recent advances in stereology for quantifying neural structure (1992)
    Springer
    Journal of neurocytology 21 (1992), S. 313-328 
    Details
    ISSN: 1573-7381
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The science of stereology has undergone a revolution over the past decade with the introduction of design-based (assumption- or model-free) methods which are highly efficient and generally unbiased. No other morphometric approach currently offers these twin benefits. Stereology is ideal for extrapolating 3-D structural quantities (real volumes, surface areas, lengths and numbers) from simple counts made on 2-D slice images. The images may take various forms (e.g. physical or optical sections, MRI slices, CT scans) but they must be sampled so as to be random in orientation and/or position if valid estimates are to be made. All the recent developments in stereology are applicable to problems in neuromorphometry. This review provides an account of major developments and the state of the art, emphasizes the importance of properly randomized sampling and identifies some applications to neural structure at different levels of organization. These include the counting and sizing of synapses, neuntes, cells and whole brains.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01191700
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