scholarly journals Postembedding Decalcification of Mineralized Tissue Sections Preserves the Integrity of Implanted Biomaterials and Minimizes Number of Experimental Animals

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Thaqif El Khassawna ◽  
Diaa Eldin S. Daghma ◽  
Sabine Stoetzel ◽  
Seemun Ray ◽  
Stefanie Kern ◽  
...  

Bone histology of decalcified or undecalcified samples depends on the investigation. However, in research each method provides different information to answer the scientific question. Decalcification is the first step after sample fixation and governs what analysis is later feasible on the sections. Besides, decalcification is favored for immunostaining and in situ hybridization. Otherwise, sample decalcification can be damaging to bone biomaterials implants that contains calcium or strontium. On the other hand, after decalcification mineralization cannot be assessed using histology or imaging mass spectrometry. The current study provides a solution to the hardship caused by material presence within the bone tissue. The protocol presents a possibility of gaining sequential and alternating decalcified and undecalcified sections from the same bone sample. In this manner, investigations using histology, protein signaling, in situ hybridization, and mass spectrometry on the same sample can better answer the intended research question. Indeed, decalcification of sections and grindings resulted in well-preserved sample and biomaterials integrity. Immunostaining was comparable to that of classically decalcified samples. The study offers a novel approach that incites correlative analysis on the same sample and reduces the number of processed samples whether clinical biopsies or experimental animals.

2020 ◽  
Author(s):  
Katerina Djambazova ◽  
Dustin R. Klein ◽  
Lukasz Migas ◽  
Elizabeth Neumann ◽  
Emilio Rivera ◽  
...  

<p>Lipids are a structurally diverse class of molecules with important biological functions including cellular signaling and energy storage. Matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS) allows for direct map-ping of biomolecules in tissue. Fully characterizing the structural diversity of lipids remains a challenge due to the presence of isobaric and isomeric species, which greatly complicates data interpretation when only <i>m/z </i>information is available. Integrating ion mobility separations aids in deconvoluting these complex mixtures and addressing the challenges of lipid IMS. Here we demonstrate that a MALDI quadrupole time-of-flight (Q-TOF) mass spectrometer with trapped ion mobility spectrometry (TIMS) enables approximately a ~270% increase in the peak capacity during IMS experiments. MALDI TIMS-MS separation of lipid isomer standards, including sn-backbone isomers, acyl chain isomers, as well as double bond positional and geometric isomers are demonstrated. As a proof-of-concept, <i>in situ </i>separation and imaging of lipid isomers with distinct spatial distributions was performed using tissue sections from a whole-body mouse pup.</p>


2020 ◽  
Author(s):  
Katerina Djambazova ◽  
Dustin R. Klein ◽  
Lukasz Migas ◽  
Elizabeth Neumann ◽  
Emilio Rivera ◽  
...  

<p>Lipids are a structurally diverse class of molecules with important biological functions including cellular signaling and energy storage. Matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS) allows for direct map-ping of biomolecules in tissue. Fully characterizing the structural diversity of lipids remains a challenge due to the presence of isobaric and isomeric species, which greatly complicates data interpretation when only <i>m/z </i>information is available. Integrating ion mobility separations aids in deconvoluting these complex mixtures and addressing the challenges of lipid IMS. Here we demonstrate that a MALDI quadrupole time-of-flight (Q-TOF) mass spectrometer with trapped ion mobility spectrometry (TIMS) enables approximately a ~270% increase in the peak capacity during IMS experiments. MALDI TIMS-MS separation of lipid isomer standards, including sn-backbone isomers, acyl chain isomers, as well as double bond positional and geometric isomers are demonstrated. As a proof-of-concept, <i>in situ </i>separation and imaging of lipid isomers with distinct spatial distributions was performed using tissue sections from a whole-body mouse pup.</p>


2020 ◽  
Author(s):  
Katerina Djambazova ◽  
Dustin R. Klein ◽  
Lukasz Migas ◽  
Elizabeth Neumann ◽  
Emilio Rivera ◽  
...  

<p>Lipids are a structurally diverse class of molecules with important biological functions including cellular signaling and energy storage. Matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS) allows for direct map-ping of biomolecules in tissue. Fully characterizing the structural diversity of lipids remains a challenge due to the presence of isobaric and isomeric species, which greatly complicates data interpretation when only <i>m/z </i>information is available. Integrating ion mobility separations aids in deconvoluting these complex mixtures and addressing the challenges of lipid IMS. Here we demonstrate that a MALDI quadrupole time-of-flight (Q-TOF) mass spectrometer with trapped ion mobility spectrometry (TIMS) enables approximately a ~270% increase in the peak capacity during IMS experiments. MALDI TIMS-MS separation of lipid isomer standards, including sn-backbone isomers, acyl chain isomers, as well as double bond positional and geometric isomers are demonstrated. As a proof-of-concept, <i>in situ </i>separation and imaging of lipid isomers with distinct spatial distributions was performed using tissue sections from a whole-body mouse pup.</p>


Endocrinology ◽  
2008 ◽  
Vol 149 (7) ◽  
pp. 3274-3278 ◽  
Author(s):  
Kristin E. Burnum ◽  
Susanne Tranguch ◽  
Deming Mi ◽  
Takiko Daikoku ◽  
S. K. Dey ◽  
...  

A reciprocal interaction between the implantation-competent blastocyst and receptive uterus is an absolute requirement for implantation, a process crucial for pregnancy success. A comprehensive understanding of this interaction has yet to be realized. One major difficulty in clearly defining this discourse is the complexity of the implantation process involving heterogeneous cell types of both the uterus and blastocyst, each endowed with unique molecular signatures that show dynamic changes during the course of pregnancy. Whereas gene expression studies by in situ hybridization or immunohistochemistry have shown differential expression patterns of specific genes during implantation, there is no report how numerous signaling proteins are spatially displayed at specific times and stages of implantation in the context of blastocyst-uterine juxtaposition. Using in situ imaging (matrix assisted laser desorption/ionization) mass spectrometry directly on uterine sections, here we provide molecular composition, relative abundance, and spatial distribution of a large number of proteins during the periimplantation period. This approach has allowed us for the first time to generate in situ proteome profiles of implantation and interimplantation sites in mice in a region- and stage-specific manner with the progression of implantation. This application is reliable because patterns of expression of several proteins displayed by in situ imaging mass spectrometry correlate well with in situ hybridization results. More interestingly, the use of this approach has provided new insights regarding uterine biology of cytosolic phospholipase A2α null females that show implantation defects.


Peptides ◽  
2017 ◽  
Vol 87 ◽  
pp. 20-27 ◽  
Author(s):  
Erik Bivehed ◽  
Robert Strömvall ◽  
Jonas Bergquist ◽  
Georgy Bakalkin ◽  
Malin Andersson

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