Electron spectroscopic diffraction and imaging of the early and mature stages of calcium phosphate formation in the epiphyseal growth plate

Barckhaus, R.H.; Höhling, H. J.; Fromm, I.; Hirsch, P. B.; Reimer, Ludwig

doi:10.1111/j.1365-2818.1991.tb03126.x

Cited by 22 publications

(10 citation statements)

References 35 publications

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“…In addition, the mineralization of the MVs expands continuously, as chains of dots and needles, outside the MV membrane in radial directions to form the mineralized nodules ( Fig. 4) (Höhling et al, 1976(Höhling et al, , 1995Wuthier, 1982;Arsenault et al, 1988;Höhling, 1989;Barckhaus et al, 1991).…”

Section: Resultsmentioning

confidence: 99%

Early mineralization of matrix vesicles in the epiphyseal growth plate

Plate

Tkotz

Wiesmann

et al. 1996

Journal of Microscopy

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Matrix vesicles (MVs) induce the primary mineralization in collagen-rich hard tissues such as bone, mineralizing cartilage and dentine. Calcium and phosphate ions accumulate at the inner MV membrane. This accumulation takes place in association with phospholipids alone and/or in association with Annexin V, which displays Ca ion channel activity when inserted in membranes; consequently, Annexin V may be involved in Ca uptake by matrix vesicles. The first crystal nuclei are formed at these macromolecules of the MV inner membrane. They grow to stable nanometre-sized particles, dots, which coalesce to form chains of dots along the macromolecules of the MV inner membrane. At the same time, or shortly afterwards, chains of these Ca phosphate dots also develop inside the MVs. The measured centre-to-centre distances between these dots represent approximately the distances between the nucleating sites, called active sites, along the MV matrix molecules. The mineralization does not stop at the MV membrane but expands continuously into the extravesicular region in radial directions to form nodules. These radiating Ca phosphate chains, which coalesce to form needles, are composed of such primary dots, which have developed at the nucleating sites of the corresponding macromolecules.

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Section: Resultsmentioning

confidence: 99%

Early mineralization of matrix vesicles in the epiphyseal growth plate

Plate

Tkotz

Wiesmann

et al. 1996

Journal of Microscopy

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“…Previous EFTEM investigations of mineral distribution in calcified tissues showed the Ca and P to be localized in calcified matrix or intracellular regions. (48,49,(51)(52)(53)(54)(55)(56)(57) Various courses of tissue preparation, including rapid freeze/freeze substitution, (48,53,56) rapid freeze/freeze dry, (52,55) glycerol treatment, (54) and conventional chemical fixation (49,51,57) were used for this elemental analysis. In the present study, aldehyde fixation, followed by freeze substitution, in which the specimens were dehydrated simultaneously and osmiumpostfixed at Ϫ80°C were used.…”

Section: Discussionmentioning

confidence: 99%

Localizational Alterations of Calcium, Phosphorus, and Calcification-Related Organics Such as Proteoglycans and Alkaline Phosphatase During Bone Calcification

Hoshi

Ejiri

Ozawa

2001

Journal of Bone and Mineral Research

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To further approach the mechanisms of bone calcification, embryonic rat calvariae were observed at electron microscopic level by the means of fine structures and various cytochemical localizations, including nonspecific proteoglycan (PG) stained by cuprolinic blue (CB), decorin, chondroitin sulfate, hyaluronan, and alkaline phosphatase (ALP), as well as the elemental mapping of calcium (Ca) and phosphorus (P) by energy-filtering transmission electron microscopy (EFTEM). In the calvariae, calcification advanced as the distance from osteoblasts increased. Closer to the osteoblasts, the osteoid was marked by an abundance of CB-positive PGs around collagen fibrils. After crystallization within matrix vesicles, calcified nodules formed and expanded, creating a coherent calcified matrix. The sizes of CB-positive PG-like structures diminished as calcification proceeded. Although small CB-positive structures were accumulated in early stage-calcified nodules, they were localized along the periphery of larger calcified nodules. Cytochemical tests for decorin, chondroitin sulfate, and hyaluronan determined their presence in the areas around collagen fibrils of the osteoid, as well as in and around calcified nodules, whereas ALP was found in the matrix vesicles, as well as in and around the calcified nodules. Ca tended to localize at the PG sites, while P often mapped to the collagen fibril structures, in the uncalcified matrix. In contrast, Ca/P colocalization was visible in and around the calcified nodules, where ALP and smaller CB-positive structures were observed. The difference in the localization patterns of Ca and P in uncalcified areas may limit the local [Ca

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“…Interpretations of concentration differences have been demonstrated to be unreliable due to mass-thickness variations (Fig. 4, see also Barckhaus et al, 1991;Leapman & Ornberg, 1988). Even for visual interpretation, these effects have to be removed.…”

Section: Discussionmentioning

confidence: 99%

Quantitative electron spectroscopic imaging in bio‐medicine: evaluation and application

Beckers¹,

Gelsema²,

Bruijn³

et al. 1996

Journal of Microscopy

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Electron spectroscopic imaging (ESI) with the energy-filtering transmission electron microscope enables the investigation of chemical elements in ultrathin biological sections. An analysis technique has been developed to calculate elemental maps and quantitative distributions from ESI sequences. Extensive experience has been obtained with a practical implementation of this technique. A procedure for more robust element detection has been investigated and optimized. With the use of Fe-loaded Chelex beads, the measurement system has been evaluated with respect to the linearity of the element concentration scale, the reproducibility of the measurements and the visual usage of image results. In liver specimens of a patient with an iron storage disease the detectability of iron was tested and we tried to characterize iron-containing components. The concentration measurement scale is approximately linear up to a relative section thickness of approximately equal to 0.5. Monitoring of this parameter is therefore considered to be important. The reproducibility was measured in an experiment with Fe-Chelex. The iron concentration differed by 6.4% between two serial measurements. Element distributions are in many applications interpreted visually. For this purpose the frequently used net-intensity distributions are regarded as unsuitable. For the quantification and visual interpretation of concentration differences mass thickness correction has to be performed. By contrast, for the detection of elements the signal-to-noise ratio is the appropriate criterion. Application of ESI analysis demonstrated the quantitative chemical capabilities of this technique in the investigation of iron storage diseases. Based on an assumed ferritin iron loading in vivo, different iron components can be discerned in liver parenchymal cells of an iron-overloaded patient.

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Electron spectroscopic diffraction and imaging of the early and mature stages of calcium phosphate formation in the epiphyseal growth plate

Cited by 22 publications

References 35 publications

Early mineralization of matrix vesicles in the epiphyseal growth plate

Early mineralization of matrix vesicles in the epiphyseal growth plate

Localizational Alterations of Calcium, Phosphorus, and Calcification-Related Organics Such as Proteoglycans and Alkaline Phosphatase During Bone Calcification

Quantitative electron spectroscopic imaging in bio‐medicine: evaluation and application

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