scholarly journals Cytokine expression and ultrastructural alterations in fresh-frozen, freeze-dried and γ-irradiated human amniotic membranes

2016 ◽  
Vol 17 (3) ◽  
pp. 399-406 ◽  
Author(s):  
Adolfo Paolin ◽  
Diletta Trojan ◽  
Antonio Leonardi ◽  
Stefano Mellone ◽  
Antonio Volpe ◽  
...  
Keyword(s):  
Cytokine Expression ◽  
Ultrastructural Alterations ◽  
Freeze Dried ◽  
Fresh Frozen ◽  
Amniotic Membranes

scholarly journals Growth Dynamic of Allogeneic and Autogenous Bone Grafts in a Vertical Model

2018 ◽  
Vol 29 (4) ◽  
pp. 325-334 ◽  
Author(s):  
Julio Leonardo de Oliveira Lima ◽  
Daniel Isaac Sendyk ◽  
Wilson Roberto Sendyk ◽  
Cristiane Ibanhes Polo ◽  
Luciana Correa ◽  
...  
Keyword(s):  
Bone Formation ◽  
Bone Growth ◽  
Pure Titanium ◽  
Bone Grafts ◽  
Autogenous Bone ◽  
Growth Dynamic ◽  
Freeze Dried ◽  
Fresh Frozen ◽  
Hollow Cylinders ◽  
Autogenous Bone Grafts

Abstract Several techniques have been proposed for vertical bone regeneration, and many of them use bone autogenous and allogeneic grafts. The purpose of this study was to compare demineralised freeze-dried bone allografts (DFDBA), fresh-frozen (FF) allografts, autogenous bone grafts to find differences between volumetric and histological quantity of bone formation and vertical bone growth dynamic. A vertical tissue regeneration bone model was performed in rabbit calvarias under general anaesthesia. Four hollow cylinders of pure titanium were screwed onto external cortical bone calvarias in eight rabbits. Each one of the cylinders was randomly filled with one intervention: DFDBA, FF, autogenous bone, or left to be filled with blood clot (BC) as control. Allogeneic grafts were obtained from a ninth animal following international standardised protocols for the harvesting, processing, and cryopreservation of allografts. Autogenous graft was obtained from the host femur scraping before adapting hollow cylinders. Animals were euthanized at 13 weeks. Vertical volume was calculated after probe device measurements of the new formed tissue inside the cylinders and after titanium cylinders were removed. Histomorphometry and fluorochrome staining were used to analyse quantity and dynamic of bone formation, respectively. Results showed that DFDBA and fresh-frozen bone improved the velocity and the quantity of bone deposition in distant portions of the basal plane of grafting. Remaining material in allograft groups was more intense than in autogenous group. Both allografts can be indicated as reliable alternatives for volume gain and vertical bone augmentation.

Repeatability of in vitro digestibility assays of forages when using fresh, frozen or freeze-dried cow faeces instead of sheep rumen liquor as sources of micro-organisms

1995 ◽  
Vol 1995 ◽  
pp. 110-110 ◽  
Author(s):  
S Akhter ◽  
E Owen ◽  
M K Theodorou ◽  
S L Tembo ◽  
E R Deaville
Keyword(s):  
Freeze Drying ◽  
Rumen Fluid ◽  
In Vitro Digestibility ◽  
Two Stage ◽  
Freeze Dried ◽  
Fresh Frozen ◽  
Sheep Rumen ◽  
Micro Organisms

Previous studies (El Shaer, Omed and Axford, 1987; Akhter, Owen, Fall, O'Donovan and Theodorou, 1994) with the two-stage in vitro procedure of Tilley and Terry (1963) have shown a high correlation between digestibilities of forages as determined using either sheep rumen liquor, sheep faeces or cow faeces as the microbial inoculum. In the first study of the of the present investigation one objective was to examine the repeatability of these digestibility measurements when made on different occasions. A second objective was to assess whether the correlations between faecal and rumen fluid based inocula could be improved if microorganisms were obtained from pairs rather than individual animals. The objective in the second study using forages of known in vivo digestibility, was to investigate the effect of freezing or freeze-drying of faeces on the repeatability of digestibilities of forages determined in vitro using micro-organisms from cow faeces.

scholarly journals Vapor fixation for immunocytochemistry and X-ray microanalysis on cryoultramicrotome sections.

1984 ◽  
Vol 32 (6) ◽  
pp. 636-642 ◽  
Author(s):  
P M Frederik ◽  
P H Bomans ◽  
W M Busing ◽  
R Odselius ◽  
W M Hax
Keyword(s):  
Exocrine Pancreas ◽  
Osmium Tetroxide ◽  
Protein A ◽  
Alpha Amylase ◽  
X Ray ◽  
Freeze Dried ◽  
Frozen Tissue ◽  
Formaldehyde Vapor ◽  
Fresh Frozen ◽  
Subcellular Level

Several organic and inorganic vapor fixatives have been tested for their ability to stabilize the ultrastructure of freeze-dried thin cryosections. The vapors from osmium tetroxide and dry formaldehyde gave a good preservation of the ultrastructure. Fixation in formaldehyde vapor preserved the immunoreactivity of alpha-amylase in exocrine pancreas, as was demonstrated with an indirect labeling technique using anti-alpha-amylase and protein A-gold. A major advantage of the use of vapor fixation is that cryosections from a specimen of fresh-frozen tissue can be used for immunocytochemistry as well as for X-ray microanalysis, as was demonstrated for the exocrine pancreas. This opens the possibility of localizing atomic species (X-ray microanalysis) and molecular species (immunocytochemistry) at the subcellular level on thin cryosections from the same tissue block.

Particle size influence in an impaction bone grafting model. Comparison of fresh-frozen and freeze-dried allografts

2009 ◽  
Vol 42 (14) ◽  
pp. 2238-2242 ◽  
Author(s):  
Olivier Cornu ◽  
Thomas Schubert ◽  
Xavier Libouton ◽  
Olivier Manil ◽  
Bernard Godts ◽  
...  
Keyword(s):  
Particle Size ◽  
Bone Grafting ◽  
Model Comparison ◽  
Impaction Bone Grafting ◽  
Freeze Dried ◽  
Fresh Frozen

Large Scale Plasma Thawing for Factor VIII Recovery

1979 ◽  
Author(s):  
P. R. Foster ◽  
J. Hunter ◽  
A. J. Dickson ◽  
B. J. White
Keyword(s):  
Factor Viii ◽  
Large Scale ◽  
Pilot Scale ◽  
Fresh Frozen Plasma ◽  
Temperature Dependent ◽  
Fluid Removal ◽  
Freeze Dried ◽  
Fresh Frozen ◽  
Major Loss ◽  
Thawing Rate

Freeze dried factor VIII concentrate of intermediate purity is widely accepted as the product of choice in the treatment of haemophilia A, yet supply of this material from National resources is inadequate. Substantial loss of factor VIII can occur during the production process and a point of major loss exists when plasma is thawed for removal of cryoprecipitate. The scale of operation is important since little or no loss occurs on small-volume thawing (i.e. 1-2ml) due to the shorter time of exposure to damaging conditions such as extremes of pH and ionic strength or enzyme attack. To overcome this the rate of thaw must be maximised within the constraint provided by factor VIII solubility, which is temperature dependent.To design a satisfactory process we have used pilot-scale equipment to study continuous thawing, utilising fluid removal for temperature control. For batch thawing of crushed plasma, at a rate of 20 1/hr, plasma temperatures ranged up to 7°C but for continuou thawing remained below 1.2°C. A thawing rate of 80 1/hr has been achieved with the temperature held below 2°C throughout. Plasma pools of up to 150 litres in volume have been handled in this way with a mean residence time of 12 minutes and this has encouraged us to design prototype equipment for use with fresh frozen plasma.

P91. Freeze-Dried versus Fresh-Frozen Allograft for Anterior Lumbar Interbody Fusion as Part of a Circumferential Fusion

2006 ◽  
Vol 6 (5) ◽  
pp. 126S-127S
Author(s):  
John Thalgott ◽  
James Giuffre ◽  
Madilyne Fogarty ◽  
Stephani Christenson ◽  
Alex Epstein ◽  
...  
Keyword(s):  
Interbody Fusion ◽  
Anterior Lumbar Interbody Fusion ◽  
Lumbar Interbody Fusion ◽  
Freeze Dried ◽  
Circumferential Fusion ◽  
Fresh Frozen

scholarly journals FROZEN THIN SECTIONS OF FRESH TISSUE FOR ELECTRON MICROSCOPY, WITH A DESCRIPTION OF PANCREAS AND LIVER

1971 ◽  
Vol 51 (3) ◽  
pp. 772-804 ◽  
Author(s):  
A. Kent Christensen
Keyword(s):  
Cutting Temperature ◽  
Freezing Damage ◽  
Nitrogen Gas ◽  
Fresh Tissue ◽  
Simple Method ◽  
Thin Sections ◽  
Low Contrast ◽  
Freeze Dried ◽  
Frozen Tissue ◽  
Fresh Frozen

A simple method has been developed that allows frozen thin sections of fresh-frozen tissue to be cut on a virtually unmodified ultramicrotome kept at room temperature. A bowl-shaped Dewar flask with a knifeholder in its depths replaces the stage of the microtome; a bar extends down into the bowl from the microtome's cutting arm and bears the frozen tissue near its lower end. When the microtome is operated, the tissue passes a glass or diamond knife in the depths of the bowl as in normal cutting. The cutting temperature is maintained by flushing the bowl with cold nitrogen gas, and can be set anywhere from about -160°C up to about -30°C. The microtome is set for a cutting thickness of 540–1000 A. Sections are picked up from the dry knife edge, and are placed on membrane-coated grids, flattened with the polished end of a copper rod, and either dried in nitrogen gas or freeze-dried. Throughout the entire process the tissue is kept cold and does not come in contact with any solvent. The morphology seen in frozen thin sections of rat pancreas and liver generally resembles that in conventional preparations, although freezing damage and low contrast limit the detail that can be discerned. Among unusual findings is a frequent abundance of mitochondrial granules in material prepared by this method.

Sign in / Sign up

Export Citation Format

Share Document