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Injury Zone (injury + zone)

Distribution by Scientific Domains

Life Sciences	50%

Selected Abstracts

Protection of corticospinal tract neurons after dorsal spinal cord transection and engraftment of olfactory ensheathing cells

GLIA, Issue 4 2006
Masanori Sasaki
Abstract Transplantation of olfactory ensheathing cells (OECs) into the damaged rat spinal cord leads to directed elongative axonal regeneration and improved functional outcome. OECs are known to produce a number of neurotrophic molecules. To explore the possibility that OECs are neuroprotective for injured corticospinal tract (CST) neurons, we transplanted OECs into the dorsal transected spinal cord (T9) and examined primary motor cortex (M1) to assess apoptosis and neuronal loss at 1 and 4 weeks post-transplantation. The number of apoptotic cortical neurons was reduced at 1 week, and the extent of neuronal loss was reduced at 4 weeks. Biochemical analysis indicated an increase in BDNF levels in the spinal cord injury zone after OEC transplantation at 1 week. The transplanted OECs associated longitudinally with axons at 4 weeks. Thus, OEC transplantation into the injured spinal cord has distant neuroprotective effects on descending cortical projection neurons. © 2005 Wiley-Liss, Inc. [source]

Chill injury in the eggs of the migratory locust, Locusta migratoria (Orthoptera: Acrididae): the time-temperature relationship with high-temperature interruption

INSECT SCIENCE, Issue 3 2005
XIAO-HONG JING
Abstract Mortality of the overwintering egg of the migratory locust, Locusta migratoria L., was attributed to chill injury because of its occurrence well above the egg's super cooling point. In this study, two parameters, upper limit of chill injury zone (ULCIZ) and sum of the injurious temperature (SIT), were used to examine the locust egg's cold hardiness. The value of ULCIZ for the locust egg is 1.06 ± 0.54°C, and the SIT is -329.7 (hour · degree). The superoxide dismutase (SOD) and catalase (CAT) activities changed dramatically after cold stress, indicating that oxygen and hydroxide free radicals are probably efficiently detoxified at low temperatures. It was suggested that the nature of chill injury in locust egg might be a complex of metabolic disorder and a non-proportional decrease in enzymatic reaction and transports, because the LDH activity at low temperature increased significantly and the ATPase activity decreased with prolonged duration of exposure to low temperatures. The results from high temperature interruption revealed that the high temperature intervals significantly increased the survival of locust eggs. [source]

The effects of multiple passes on the epidermal thermal damage pattern in nonablative fractional resurfacing,

LASERS IN SURGERY AND MEDICINE, Issue 2 2009
Dieter Manstein MD
Background and Objective Nonablative fractional resurfacing is a concept of cutaneous re-modeling whereby laser-induced microscopic treatment zones (MTZs) are surrounded by normal viable tissue. Such thermal damage pattern with a small diameter of individual lesions allows fast re-epithelialization with minimal side effects. The purpose of this in vitro study was to determine the fraction of thermal injury per unit surface area (fill factor) and lesion size in relation to pulse energy and number of passes. Methods Full thickness abdominal skin samples were exposed ex vivo to the Fraxel SR 750 laser (Reliant Technologies, Mountain View, CA). One set of exposures was performed for pulse energies in the range of 8 to 40 mJ for a single pass at 250 MTZ/cm2. A second set of exposures was performed at 10 mJ with number of passes from 1 to 30. The thermal damage pattern was assessed by incubation of epidermal sheets with NitroBlueTetrazoliumChloride (NBTC) stain. Size of individual MTZ and fill factor were determined by image analysis (ImageJ, NIH, Bethesda, MD) of digital micrographs. Results Width of the thermal injury zone was directly related to the pulse energy used. The fill factor did not have a uniform relationship with the number of passes. Due to the stochastic placement of individual MTZs, even for greater number of passes, some residual undamaged tissue was found. Due to formation of thermal damage clusters, defined as overlapping individual MTZs, the size of the resulting clustering lesions which we defined as microscopic treatment cluster (MTC) increased linearly as a function of the number of passes. Conclusion We have described the fill factor as it relates to the number of passes and have demonstrated that the average size of individual lesions depends on the number of passes. Clustering of MTZs lead to the development of MTC, the average size of which increased with the number of passes. The clinical implications of these findings are contingent on further studies. Lasers Surg. Med. 41:149,153, 2009. © 2009 Wiley-Liss, Inc. [source]

Selective transcutaneous delivery of energy to porcine soft tissues using intense ultrasound (IUS),,

LASERS IN SURGERY AND MEDICINE, Issue 2 2008
W. Matthew White MD
Abstract Objective Various energy delivery systems have been utilized to treat superficial rhytids in the aging face. The Intense Ultrasound System (IUS) is a novel modality capable of transcutaneously delivering controlled thermal energy at various depths while sparing the overlying tissues. The purpose of this feasibility study was to evaluate the response of porcine tissues to various IUS energy source conditions. Further evaluation was performed of the built-in imaging capabilities of the device. Materials and Methods Simulations were performed on ex vivo porcine tissues to estimate the thermal dose distribution in tissues after IUS exposures to determine the unique source settings that would produce thermal injury zones (TIZs) at given depths. Exposures were performed at escalating power settings and different exposure times (in the range of 1,7.6 J) using three IUS handpieces with unique frequencies and focal depths. Ultrasound imaging was performed before and after IUS exposures to detect changes in tissue consistency. Porcine tissues were examined using nitro-blue tetrazolium chloride (NBTC) staining sensitive for thermal lesions, both grossly and histologically. The dimensions and depth of the TIZs were measured from digital photographs and compared. Results IUS can reliably achieve discrete, TIZ at various depths within tissue without surface disruption. Changes in the TIZ dimensions and shape were observed as source settings were varied. As the source energy was increased, the thermal lesions became larger by growing proximally towards the tissue surface. Maximum lesion depth closely approximated the pre-set focal depth of a given handpiece. Ultrasound imaging detected well-demarcated TIZ at depths within the porcine muscle tissue. Conclusion This study demonstrates the response of porcine tissue to various energy dose levels of Intense Ultrasound. Further study, especially on human facial tissue, is necessary in order to understand the utility of this modality in treating the aging face and potentially, other cosmetic applications. Lesers Surg. Med. 40:67,75, 2008. © 2008 Wiley-Liss, Inc. [source]