Expression of cannabinoid receptor I during mice skin incised wound healing course / 法医学杂志

OBJECTIVE@#To investigate the expression of cannabinoid receptor I (CB1R) during mice skin incised wound healing course and time-dependent changes of CB1R in wound age determination.@*METHODS@#The changes of CBIR expression in skin incised wound were detected by immunohistochemistry and Western blotting.@*RESULTS@#The control group showed a low expression of CB1R detected mainly in epidermis, hair follicles, sebaceous gland and dermomuscular layer. CB1R expression was undetectable in neutrophils in the wound specimens from 6h to 12h post-injury. CB1R positive cells were mostly mononuclear cells (MNCs) and fibroblastic cells (FBCs) from 1 d to 5 d post-injury. CB1R positive cells were mostly FBCs from 7 d to 14d post-injury. The ratio of the CB1R positive cells increased gradually in the wound specimens from 6 h to 3 d post-injury, reached peak level at 5 d, and then decreased gradually from 7d to 14 d post-injury. The positive bands of CB1R were observed in all time points of the wound healing course by Western blotting. The expression peak showed at 5 d post-injury.@*CONCLUSION@#CB1R is activated during the wound healing course. The expression of CB1R is found in mononuclear cells, which could be involved in inflammation reaction. CBIR is observed in fibroblastic cells, which could participate in the wound healing. CB1R may be a potentially useful marker for determination of wound healing age.

Expression of M3 subtype of muscarinic receptor during the skin incised wound healing in mice / 法医学杂志

OBJECTIVE@#To investigate the expression of M3 subtype of muscarinic receptors (M3R) during the incised wound healing of the skin in mice and the characteristics of its time-dependent.@*METHODS@#The change of M3R in skin incised wound was detected by immunohistochemical staining and Western blot.@*RESULTS@#M3R-positive cells were detected in epidermis, hair follicle, sebaceous glands, sweat glands, dermomuscular layer in normal mouse skin. Expression of M3R was mainly detectable in polymorphonuclear cells (PMNs) in the wound specimens aged from 6h to 12h after injury. Afterwards, the M3R-positive cells were mostly mononuclear cells (MNCs) and fibroblastic cells (FBCs) at 1 d to 3d post-injury, whereas the M3R-positive cells were mostly FBCs aged from 5 d to 14d. Morphometrically, the ratio of the M3R-positive cells increased aged from 6h to 12h after injury, with a peak at 12h. The ratios kept a high relatively level aged from 1 d to 5 d, but significantly that lowered as compared with aged 12h after injury. The ratio reached the peak at 7 d again after injury, and then decreased gradually. The M3R protein also revealed a time-dependent tendency with double peaks at 12h and 7 d after injury as detected by Western blotting.@*CONCLUSION@#M3R is time-dependently expression in PMNs, MNCs and FBCs suggesting that it may play roles during the skin incised wound healing, and M3R may be used as a marker for wound age determination.

The time-dependent changes of phospho-JNK expression during the skin incised wound healing in mice / 法医学杂志

OBJECTIVE@#To investigate the changes of phospho-JNK (p-JNK) during the incised wound healing of the skin in mice and to explore the rule of the time-dependent change of p-JNK in wound age determination.@*METHODS@#The changes of p-JNK expression in incised skin wound were detected by immunohistochemistry and Western blot.@*RESULTS@#There was a minimal baseline staining of p-JNK in control mouse skin. Changes of p-JNK expression were mainly detectable in neutrophils in the wound specimens from 3 hours to 12 hours after injury. Afterwards, the p-JNK positive cells were mostly mononuclear cells and fibroblasts between post-injury day 1 and day 5, whereas the p-JNK positive cells were mostly fibroblasts between post-injury day 7 and day 14. Morphometrically, the ratio of the p-JNK positive cells to the total increased gradually in the wound specimens from 3 hours to day 1, and maximized at day 1 with a slight decrease from post-injury day 3 to day 5. The ratio showed a second peak in the specimens of day 7, and then decreased gradually from post-injury day 10 to day 14. The changes of p-JNK expression were observed throughout the wound healing stages by Western blot as well, with a peak expression occurring between 12 hour and day 3 after injury.@*CONCLUSION@#p-JNK may play a pivotal role in inducing apoptosis of neutrophils, mononuclear cells, and fibroblasts during skin wound healing and meanwhile, p-JNK may be a potentially useful marker for wound age determination.

Animal model of grading skeletal muscle contusion due to blunt impact in rats / 法医学杂志

OBJECTIVE@#To establish a new animal model of grading skeletal muscle contusions that could be controllable and repetitive.@*METHODS@#The rats' gastrocnemius was injured by a new weight-dropping device designed. The force acting on gastrocnemius with a comparatively constant duration and inducing elastic deformation of the gastrocnemius was expressed with velocity (v) and deformation (DF). Instant velocity was changed to create gastrocnemius contusions. Pathological changes of gastrocnemius were graded by the gross and histological examinations of 39 rats.@*RESULTS@#At low level of impact (v: 2 m/s, DF: 5.5 mm), mild injuries were detected in epimysium and superficial layer of gastrocnemius. At moderate level of impact (v: 2.5 m/s, DF: 6.5 mm), the injuries were observed in epimysium and whole gastrocnemius. At high level of impact (v: 3 m/s, DF: 7.5 mm), severe injuries were seen deeper to soleus with more extensive skeletal muscle damage.@*CONCLUSION@#Grading of skeletal muscle blunt force contusion is created by parameter of velocity and muscle deformation. The model could be used for further research on skeletal muscle contusions.

Immunohistochemical study on contents of beta-amyloid, alpha-actin and collagen IV in cerebral small vessels with unknown type of pathological lesion / 法医学杂志

OBJECTIVE@#To investigate the structural characteristics of the cerebral small vessels with an unknown type of pathological lesion (UTPL).@*METHODS@#Contents of beta-amyloid, alpha-actin and collagen IV in cerebral small vessels with UTPL were studied by Congo red staining, immunohistochemical staining and computer image analysis.@*RESULTS@#The low expression levels of alpha-actin and collagen IV (P<0.05) were observed in tunica media of the vessels with UTPL, and no positive expression of beta-amyloid (P>0.05) was observed in these vessel walls. The expressions of proteins mentioned above in UTPL were different from those of cerebral amyloid angiopathy(CAA) and hyaline arteriolosclerosis.@*CONCLUSION@#UTPL was different from CAA or hyaline arteriolosclerosis in pathologic feature.