Increased expressions and activations of apoptosis-related factors in cell signaling during incised skin wound healing in mice: a preliminary study for forensic wound age estimation.

Recent studies have demonstrated that apoptosis plays a pivotal role during skin wound healing and apoptosis-related factors in cell signaling regulate a variety of cellular function. In this study, the expressions of p38MAPK, and JNK, iNOS, eNOS were detected and the activations of caspase-6, -7, -8, -9, and calpain, another signaling pathway of apoptosis, were also investigated by immunohistochemical staining and Western blotting in mice. A time-dependent increase of each protein level was observed by immunohistochemistry and Western blot in mouse skin incision. p38MAPK level peaked at 12 h and 3 d, calpain level peaked at 1 d and 5 d, iNOS level peaked at 1 d and 10 d, while the peak levels of eNOS, caspase-6, -7, -8, and -9 occurred at 3 d and p-JNK at 1 d post-injury. In the early phase of wound healing, infiltrating polymorphonulcear cells were labeled with all the factors except caspase-8. Thereafter, infiltrating mononuclear cells and proliferating spindle-shaped fibroblastic cells showed positive staining for p38MAPK, JNK, calpain, caspases and NOS. The activation of caspase-8, -9, -6, and -7 as detected by Western blot indicated that caspase apoptotic pathway may take effect in cellular elimination during skin wound healing. From the viewpoint of forensic pathology, the time-dependent expressions of the factors in apoptotic pathway during skin incised wound healing may be used as potential markers for wound age estimation.

[Expression of c-jun during the incised wound healing in mice skin].

UNLABELLED: OBJECTIVE To investigate the time-dependent expression of c-jun during the healing of incised wound in mice skin. METHODS: The expression of c-jun in different stages after the incised wound were detected by immunohistochemistry and Western blot. RESULTS: There was a low level expression of c-jun in normal mice skin. Expression of c-jun was mainly detected in neutrophils from 3 h to 12h after injury. The c-jun positive cells were almost mononuclear cells (MNCs) and fibroblasts between 1 d and 5 d after injury. The c-jun positive cells were mostly fibroblasts between 7 d and 14 d after injury. The ratio of the c-jun positive cells increased in the wound specimens from 3 h to 12 h, peaked at 12 h, declined partially from 1 d to 5 d, and reached the peak secondly at 7 d, then decreased from 10 d to 14 d. The expression of c-jun was observed throughout the wound healing stages by Western blot with two peaks occurring at 12 h and 7 d after injury. CONCLUSION: The c-jun may play a potential role in inducing apoptosis of neutrophils, MNCs and fibroblasts during skin wound healing, and it may be used as the marker for wound age determination.

[The application of biochemical indexes detecting in sudden cardiac death in forensic autopsy].

Sudden cardiac death(SCD) from early myocardial ischemia is often lack of typically morphological findings and clinical manifestation, thus cases of SCD may be suspected as criminal cases. It is necessary to clarify the cause of death, which is significance for medico-legal investigation. This article reviewed the latest advancement in the studies on the application of inorganic ions, CK-MB, cTn, ANP and BNP for certification of death from SCD in order to provide a practical way for diagnosis of SCD in forensic pathology.

[Changes of phospho-JNK expression during the skin burned wound healing].

OBJECTIVE: To observe the changes of expression of phosphorylation c-Jun NH2-terminal kinase (p-JNK) during the skin burned wound healing in patients and discuss the molecular mechanism of burned wound healing. METHODS: The staining intensity and distribution of p-JNK were detected by immunohistochemistry and routine histology in burned skin samples of 12 patients and normal skin samples of 12 control subjects. RESULTS: In normal skin, the positive signals of p-JNK were mostly localized in basal layer cells of the epidermis, with a positive rate of (8.8+/-1.3)%. In the burned group, the positive signals of p-JNK were mainly localized in the epidermal cells and some inflammatory cells, with a significantly higher positive rate of (31.2+/-3.3)% than the normal group(P<0.01). CONCLUSION: The changes of p-JNK expression after skin burned might correlate with wound healing.

[The time-dependent changes of phospho-JNK expression during the skin incised wound healing in mice].

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.