scholarly journals Subfreezing versus Room-Temperature Balloon Dilation of Benign Tracheal Stenosis: A Pilot Study in Rabbits

2013 ◽  
Vol 92 (5) ◽  
pp. 219-222
Author(s):  
Benjamin J. Wycherly ◽  
Matthew K. Steehler ◽  
Hosai Hesham ◽  
Kevin Burke ◽  
Sonya Malekzadeh
Keyword(s):  
New Zealand ◽  
Pilot Study ◽  
Tracheal Stenosis ◽  
Room Temperature ◽  
Balloon Dilation ◽  
Collagen Content ◽  
Collagen Deposition ◽  
Tracheal Injury ◽  
New Zealand White Rabbits

We conducted an experiment to compare collagen deposition in tracheal stenoses dilated with room-temperature balloons and stenoses dilated with balloons at a subfreezing temperature (-10°C). Six New Zealand white rabbits underwent endoscopic tracheal injury. Tracheal dilation was performed at 3 weeks postinjury with either a room-temperature balloon or a vascular cryoplasty balloon. Five surviving rabbits were sacrificed at either 2 weeks (n = 3) or 4 weeks (n = 2) postdilation (1 rabbit that was not able to tolerate dilation was euthanized during the procedure). A blinded pathologist graded histologic sections of the injured tracheas for collagen content. The tracheal collagen deposits in the 3 animals sacrificed at 2 weeks postdilation were all graded as moderate. However, at the 4-week postdilation examination, there was a marked difference in collagen deposition between the rabbit that underwent room-temperature dilation and the rabbit that underwent subfreezing dilation; while the former showed moderate collagen deposition, the deposition in the latter was only mild. In conclusion, this pilot study showed that tracheal dilation with balloon cryotherapy decreased collagen deposition in the injured airway of 1 animal. Larger studies are required to determine whether balloon cryotherapy improves the long-term patency of immature tracheal stenosis.

R453 – Cryoballoon Dilation of Tracheal Stenosis

2008 ◽  
Vol 139 (2_suppl) ◽  
pp. P196-P197
Author(s):  
Benjamin Wycherly ◽  
Sonya Malekzadeh ◽  
Matthew Kirk Steehler ◽  
Burke Kevin ◽  
Bhaskar Kallakury
Keyword(s):  
Tracheal Stenosis ◽  
Room Temperature ◽  
Endoscopic Management ◽  
Collagen Deposition ◽  
Tracheal Injury ◽  
Post Injury ◽  
New Zealand White Rabbits ◽  
Mucosal Thickness ◽  
Preliminary Study

Problem The endoscopic management of tracheal stenosis remains ineffective, despite advances in dilation and resection techniques. The vascular literature reveals improved patency rates of stenosis with cryodilation compared to balloon angioplasty. The proposed mechanism is a decrease in collagen deposition with cryotherapy. Similarly, tracheal cryotherapy maintains the cartilaginous framework of the airway while minimizing collagen deposition. The objective of this study is to compare collagen deposition in tracheal injuries dilated with room temperature versus subfreezing temperature balloons. Methods Six New Zealand White rabbits underwent endoscopic tracheal injury with a nylon brush. At 3 weeks post injury, dilation was performed by a balloon inflated with either room temperature saline (n=3), or nitrous oxide to −10 °C, (n=3). Rabbits were sacrificed at 2 and 4 weeks post dilation. Segments of injured trachea were histologically examined for collagen and graded as none, mild, moderate, or severe. Results Collagen deposition at 2 weeks post dilation was graded as moderate to severe in all specimens. In the 4 week post dilation tracheas, marked differences in collagen deposition were noted. While the trachea dilated at room temperature was graded as moderate to severe, the cryoballoon dilated trachea showed minimal to no collagen deposition. Despite the observed differences in collagen deposition, sub-mucosal thickness differed between specimens by an average of 0.2 mm. Conclusion This preliminary study suggests that dilation with balloon cryotherapy decreases collagen deposition in the injured airway. Significance Long-term patency of immature tracheal stenosis may be improved with the addition of subfreezing temperatures to endoscopic dilation techniques. Support A grant was provided by Boston Scientific, Inc. in the form of money and supplies.

Subfreezing versus Room-Temperature Balloon Dilation of Benign Tracheal Stenosis: A Pilot Study in Rabbits

2013 ◽  
Vol 92 (4) ◽  
pp. 219-222
Author(s):  
Benjamin J. Wycherly ◽  
Matthew K. Steehler ◽  
Hosai Hesham ◽  
Kevin Burke ◽  
Sonya Malekzadeh
Keyword(s):  
Pilot Study ◽  
Tracheal Stenosis ◽  
Room Temperature ◽  
Balloon Dilation

Hypercholesterolemia-Induced Long-Term Increase of Macrophages in the Myocardium of New Zealand White Rabbits

2003 ◽  
Vol 174 (4) ◽  
pp. 184-193 ◽  
Author(s):  
Ralf Kinscherf ◽  
Huse Kamencic ◽  
Hans-Peter Deigner ◽  
Jürgen Metz
Keyword(s):  
New Zealand ◽  
New Zealand White Rabbits

Cholesterol diet and effect of long-term withdrawal on plaque development and composition in the thoracic aorta of New Zealand White rabbits

2010 ◽  
Vol 210 (2) ◽  
pp. 407-413 ◽  
Author(s):  
Karen Riedmüller ◽  
Stephan Metz ◽  
Gabriel A. Bonaterra ◽  
Olaf Kelber ◽  
Dieter Weiser ◽  
...  
Keyword(s):  
New Zealand ◽  
Thoracic Aorta ◽  
Cholesterol Diet ◽  
Plaque Development ◽  
New Zealand White Rabbits

scholarly journals Comparison of Biocompatibility and Biodegradability of Poly(Lactic-Co-Glycolic Acid) (Plga) Combined with Autologous Fibrin Versus Plga for Intra-Articular Screw Fixation; An Invivo Study with New Zealand White Rabbits- The Microradiograph Outcome

2017 ◽  
Vol 16 (1) ◽  
Author(s):  
Theenesh Balakrishnan ◽  
Ahmad Hafiz Zulkifli ◽  
Munirah Sha'ban ◽  
Nurul Hafiza Mohd Jan ◽  
Mohd Zulfadzli Ibrahim ◽  
...  
Keyword(s):  
New Zealand ◽  
Biodegradable Polymers ◽  
Screw Fixation ◽  
Left Knee ◽  
Long Term Outcomes ◽  
New Zealand White Rabbits ◽  
Quantitative Integration ◽  
The Right

Introduction: The great potential of biodegradable polymers in orthopaedic surgery is gradually being recognized. PLGA is one of the common polymers used. However, long term outcomes, with regards to PLGA, are still not well documented. Hence, we attempted to study the outcome of PLGA and also its combination with fibrin. Materials and method: Objectives : 1) To compare biocompatibility and biodegradability of polymer (PLGA + fibrin) with PLGA for intra-articular screw fixation 2) to study the imaging microradiograph) features. We used fabricated PLGA scaffolds in combination with autologous fibrin for an in-vivo prospective research. Total of nine New Zealand White Rabbits (NZWR) were operated and the scaffolds were placed at both medial and lateral femoral condyles of the right knee and those with fibrin at the left knee. Post implantation, evaluation was done at 6,12 and 24 weeks (three NZWR in each group). For microradiological assessment, micro CT (Skyscan 1176) was used. Results: The combination of PLGA and fibrin has better biocompatibility, showed faster biodegradation and more quantitative integration of osseous tissues. Conclusion: Biodegradable polymer PLGA with incorporation of fibrin resulted in superior outcome compared to usage of other current biodegradable polymers.

A Cytochemical Study of Glucose-6-Phosphatase (G-6-PASE) in Cells Participating in Atherogenesis of Rabbit Aorta

1975 ◽  
Vol 33 ◽  
pp. 460-461
Author(s):  
Sidney D. Kobernick ◽  
Edna A. Elfont ◽  
Neddra L. Brooks
Keyword(s):  
Lipid Metabolism ◽  
New Zealand ◽  
Aortic Wall ◽  
Rabbit Aorta ◽  
Plaque Formation ◽  
Metabolic Changes ◽  
Atherosclerotic Plaques ◽  
Cytochemical Study ◽  
Cellular Alteration ◽  
New Zealand White Rabbits

This cytochemical study was designed to investigate early metabolic changes in the aortic wall that might lead to or accompany development of atherosclerotic plaques in rabbits. The hypothesis that the primary cellular alteration leading to plaque formation might be due to changes in either carbohydrate or lipid metabolism led to histochemical studies that showed elevation of G-6-Pase in atherosclerotic plaques of rabbit aorta. This observation initiated the present investigation to determine how early in plaque formation and in which cells this change could be observed.Male New Zealand white rabbits of approximately 2000 kg consumed normal diets or diets containing 0.25 or 1.0 gm of cholesterol per day for 10, 50 and 90 days. Aortas were injected jin situ with glutaraldehyde fixative and dissected out. The plaques were identified, isolated, minced and fixed for not more than 10 minutes. Incubation and postfixation proceeded as described by Leskes and co-workers.

Comparative Labelling and Biokinetic Studies of 99mTc-EDTA(Sn) and 99mTc-DTPA(Sn)

1977 ◽  
Vol 16 (01) ◽  
pp. 30-35 ◽  
Author(s):  
N. Agha ◽  
R. B. R. Persson
Keyword(s):  
Complex Formation ◽  
Significant Influence ◽  
Room Temperature ◽  
Ph Value ◽  
Maximum Activity ◽  
Reduction Step ◽  
Labelling Yield ◽  
Different Temperatures ◽  
Kinetics Of

SummaryGelchromatography column scanning has been used to study the fractions of 99mTc-pertechnetate, 99mTcchelate and reduced hydrolyzed 99mTc in preparations of 99mTc-EDTA(Sn) and 99mTc-DTPA(Sn). The labelling yield of 99mTc-EDTA(Sn) chelate was as high as 90—95% when 100 μmol EDTA · H4 and 0.5 (Amol SnCl2 was incubated with 10 ml 99mTceluate for 30—60 min at room temperature. The study of the influence of the pH-value on the fraction of 99mTc-EDTA shows that pH 2.8—2.9 gave the best labelling yield. In a comparative study of the labelling kinetics of 99mTc-EDTA(Sn) and 99mTc- DTPA(Sn) at different temperatures (7, 22 and 37°C), no significant influence on the reduction step was found. The rate constant for complex formation, however, increased more rapidly with increased temperature for 99mTc-DTPA(Sn). At room temperature only a few minutes was required to achieve a high labelling yield with 99mTc-DTPA(Sn) whereas about 60 min was required for 99mTc-EDTA(Sn). Comparative biokinetic studies in rabbits showed that the maximum activity in kidneys is achieved after 12 min with 99mTc-EDTA(Sn) but already after 6 min with 99mTc-DTPA(Sn). The long-term disappearance of 99mTc-DTPA(Sn) from the kidneys is about five times faster than that for 99mTc-EDTA(Sn).

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