scholarly journals Von Kossa and his staining technique

Author(s):  
Marlon R. Schneider

AbstractOne hundred and twenty years ago, the Hungarian physician Julius von Kossa developed a now classical staining method for detecting mineral deposits in animal tissues. Since then, this method has been widely adapted and combined with different counterstains, but still bears the name of its original inventor, who, if alive, would have turned 150 in 2015. As a rather inexpensive technique that does not require special instrumentation, von Kossa’s staining method became extremely popular for demonstrating mineralized tissues in vivo and in vitro. This article pays tribute to von Kossa and to his handy staining method.

Crystals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1131
Author(s):  
Maricela Santana ◽  
Gonzalo Montoya ◽  
Raúl Herrera ◽  
Lía Hoz ◽  
Enrique Romo ◽  
...  

Dental cementum contains unique molecules that regulate the mineralization process in vitro and in vivo, such as cementum protein 1 (CEMP1). This protein possesses amino acid sequence motifs like the human recombinant CEMP1 with biological activity. This novel cementum protein 1-derived peptide (CEMP1-p3, from the CEMP1’s N-terminal domain: (QPLPKGCAAVKAEVGIPAPH), consists of 20 amino acids. Hydroxyapatite (HA) crystals could be obtained through the combination of the amorphous precursor phase and macromolecules such as proteins and peptides. We used a simple method to synthesize peptide/hydroxyapatite nanocomposites using OCP and CEMP1-p3. The characterization of the crystals through scanning electron microscopy (SEM), powder X-ray diffraction (XRD), high--resolution transmission electron microscopy (HRTEM), and Raman spectroscopy revealed that CEMP1-p3 transformed OCP into hydroxyapatite (HA) under constant ionic strength and in a buffered solution. CEMP1-p3 binds and highly adsorbs to OCP and is a potent growth stimulator of OCP crystals. CEMP1-p3 fosters the transformation of OCP into HA crystals with crystalline planes (300) and (004) that correspond to the cell of hexagonal HA. Octacalcium phosphate crystals treated with CEMP1-p3 grown in simulated physiological buffer acquired hexagonal arrangement corresponding to HA. These findings provide new insights into the potential application of CEMP1-p3 on possible biomimetic approaches to generate materials for the repair and regeneration of mineralized tissues, or restorative materials in the orthopedic field.


Development ◽  
1988 ◽  
Vol 102 (4) ◽  
pp. 793-803 ◽  
Author(s):  
V.E. Papaioannou ◽  
K.M. Ebert

Total cell number as well as differential cell numbers representing the inner cell mass (ICM) and trophectoderm were determined by a differential staining technique for preimplantation pig embryos recovered between 5 and 8 days after the onset of oestrus. Total cell number increased rapidly over this time span and significant effects were found between embryos of the same chronological age from different females. Inner cells could be detected in some but not all embryos of 12–16 cells. The proportion of inner cells was low in morulae but increased during differentiation of ICM and trophectoderm in early blastocysts. The proportion of ICM cells then decreased as blastocysts expanded and hatched. Some embryos were cultured in vitro and others were transferred to the oviducts of immature mice as a surrogate in vivo environment and assessed for morphology and cell number after several days. Although total cell number did not reach in vivo levels, morphological development and cell number increase was sustained better in the immature mice than in vitro. The proportion of ICM cells in blastocysts formed in vitro was in the normal range.


1941 ◽  
Vol 73 (5) ◽  
pp. 629-640 ◽  
Author(s):  
René J. Dubos ◽  
Rollin D. Hotchkiss

Several species of aerobic sporulating bacilli recently isolated from soil, sewage, manure, and cheese, as well as authentic strains obtained from type culture collections, have been found to exhibit antagonistic activity against unrelated microorganisms. Cultures of these aerobic sporulating bacilli yield an alcohol-soluble, water-insoluble fraction,—tyrothricin,—which is bactericidal for most Gram-positive and Gram-negative microbial species. Two different crystalline products have been separated from tyrothricin. One, which may be called tyrocidine, is bactericidal in vitro for both Gram-positive and Gram-negative species; the other substance, gramicidin, is effective only against Gram-positive microorganisms. In general, tyrocidine behaves like a protoplasmic poison and like other antiseptics, loses much of its activity in the presence of animal tissues. Gramicidin on the contrary exerts a much more subtle physiological effect on the susceptible bacterial cells and, when applied locally at the site of the infection, retains in vivo a striking activity against Gram-positive microorganisms.


Biomimetics ◽  
2019 ◽  
Vol 4 (3) ◽  
pp. 48
Author(s):  
De Melo ◽  
McGinlay ◽  
Markus ◽  
Macri-Pellizzeri ◽  
Symonds ◽  
...  

Mesenchymal stem cells (MSCs) are progenitors for bone-forming osteoblasts and lipid-storing adipocytes, two major lineages co-existing in bone marrow. When isolated in vitro, these stem cells recapitulate osteoblast or adipocyte formation if treated with specialised media, modelling how these lineages interact in vivo. Osteogenic differentiation is characterised by mineral deposits accumulating in the extracellular matrix, typically assessed using histological techniques. Adipogenesis occurs with accumulation of intracellular lipids that can be routinely visualised by Oil Red O staining. In both cases, staining requires cell fixation and is thus limited to end-point assessments. Here, a vital staining approach was developed to simultaneously detect mineral deposits and lipid droplets in differentiating cultures. Stem cells induced to differentiate produced mixed cultures containing adipocytes and bone-like nodules, and after two weeks live cultures were incubated with tetracycline hydrochloride and Bodipy to label mineral- and lipid-containing structures, respectively. Fluorescence microscopy showed the simultaneous visualisation of mineralised areas and lipid-filled adipocytes in live cultures. Combined with the nuclear stain Hoechst 33258, this approach further enabled live confocal imaging of adipogenic cells interspersed within the mineralised matrix. This multiplex labelling was repeated at subsequent time-points, demonstrating the potential of this new approach for the real-time high-precision imaging of live stem cells.


2017 ◽  
Vol 242 (8) ◽  
pp. 781-787 ◽  
Author(s):  
Jessica A Williams ◽  
Katrina Zhao ◽  
Shengkan Jin ◽  
Wen-Xing Ding

Removal of damaged mitochondria through mitophagy is critical for maintaining cellular homeostasis and functions. Increasing evidence implicates mitophagy in red blood cell differentiation, neurodegeneration, macrophage-mediated inflammation, ischemia, adipogenesis, drug-induced tissue injury, and cancer. Considerable progress has been made toward understanding the biochemical mechanisms involved in mitophagy regulation. However, few reliable assays to monitor and quantify mitophagy have been developed, particularly in vivo. In this review, we summarize the recent development of three assays, MitoTimer, mt-Keima and mito-QC, for monitoring and quantifying mitophagy in cells and in animal tissues. We also discuss the advantages and limitations of these three assays when using them to monitor and quantify mitophagy. Impact statement Removal of damaged mitochondria through mitophagy is critical for maintaining cellular homeostasis and functions. However, reliable quantitative assays to monitor mitophagy, particularly in vivo, are just emerging. This review will summarize the current novel quantitative assays to monitor mitophagy in vivo.


2020 ◽  
Author(s):  
Bryan E.J. Lee ◽  
Brian Langelier ◽  
Kathryn Grandfield

AbstractBone is a complex, hierarchical structure comprised of two distinct phases: the organic, collagen– rich phase and the inorganic mineral–rich phase. This collagen–mineral arrangement has implications for bone function, aging, and disease. However, strategies to extract a single mineralized collagen fibril to investigate the interplay between components with sufficient resolution have been mostly confined to in vitro systems that only approximate the biological environment or transmission electron microscopy studies with lower spatial and chemical resolution. Therefore, there is extensive debate over the location of mineral with respect to collagen in in vivo mineralized tissues as visualization and quantification of the mineral in a living system is difficult or impossible. Herein, we have developed an approach to artificially extract a single mineralized collagen fibril from bone to analyze its composition and structure atom-by-atom with 3D resolution and sub-nanometer accuracy using atom probe tomography. This enables, for the first time, a method to probe fibril-level mineralization and collagen–mineral arrangement from an in vivo system with both the spatial and chemical precision required to comment on collagen– mineral arrangement. Using atom probe tomography, 4D (spatial + chemical) reconstructed volumes of leporine bone were generated with accuracy from correlative scanning electron microscopy. Distinct, winding collagen fibrils were identified with mineralized deposits both encapsulating and incorporated into the collagenous structures. This work demonstrates a novel fibril-level detection method that can be used to probe structural and chemical changes of bone and contribute new insights to the debate on collagen–mineral arrangement in mineralized tissues such as bones, and teeth.


1986 ◽  
Vol 64 (4) ◽  
pp. 356-362 ◽  
Author(s):  
Paul Zung ◽  
Carmelo Domenicucci ◽  
Safia Wasi ◽  
Fumiyuki Kuwata ◽  
Jaro Sodek

Osteonectin is a major glycoprotein of porcine and bovine bones and teeth that is found associated with hydroxylapatite crystal surfaces. From the ability of osteonectin to bind calcium ions, it has been proposed as a possible nucleator of hydroxylapatite crystal formation. Analysis of hydroxylapatite-bound proteins of rat bone and dentine, however, has revealed that osteonectin represents only 2.5 ± 1.5% of the hydroxylapatite-bound protein in long bones, 0.9 ± 0.5% in calvariae, and < 0.1% in incisor dentine of animals of different ages. Further, in vivo pulse–chase studies carried out in young adult rats have shown osteonectin to be synthesized at low levels in these tissues. Similarly, low levels of osteonectin were synthesized by rat calvarial cells in vitro. In contrast, fibroblastic cells from periodontal ligament and gingiva synthesized significantly greater amounts of osteonectin. These studies indicate that the low quantities of osteonectin in rat mineralized tissues are a consequence of low rates of formation rather than being due to rapid turnover. The virtual absence of osteonectin in incisor dentine correlates with the lack of peritubular dentine in rat, whereas the low osteonectin content of rat bones may reflect differences in their structure and biophysical properties compared with bones of larger mammals.


1982 ◽  
Vol 3 (4) ◽  
pp. 421-432 ◽  
Author(s):  
Andrzej Kraszewski ◽  
Maria A. Stuchly ◽  
Stanislaw S. Stuchly ◽  
Andrew M. Smith

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