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Lin Qiu

Publications and source records attributed to Lin Qiu.

22 records · Page 2Linked to original sources
PubMed2003

Activation of ERK1/2 after neonatal rat cerebral hypoxia-ischaemia.

Activation of extracellular signal-related kinases (ERK1/2), also known as p42/44 mitogen-activated protein kinase (MAPK), is considered important for neuronal survival, cell proliferation and apoptosis. In the present study, activation (phosphorylation) of ERK1/2 (P-ERK) was investigated in brains of 7-day-oldrats after hypoxia-ischaemia (HI). In damaged areas, P-ERK-positive neurons appeared immediately after HI and the staining remained for at least 8 h. At later time points, 24 and 72 h post-HI, P-ERK-positive neurons were found in the core of the infarct and in the border zone to undamaged tissue. These cells also showed signs of DNA damage and calpain-induced fodrin breakdown, indicative of injury. At 72 h post-HI, P-ERK was also observed in microglia in the border zone to the damaged area and in astrocytes and oligodendrocytes in white matter of both hemispheres. P-ERK was strongly expressed in the subventricular zone in both hemispheres after HI at most time points, although the staining in the ipsilateral (damaged hemisphere) was stronger than in the contralateral (non-damaged hemisphere). In summary, ERK1/2 activation occurred early in neurons after HI in the neonatal brain, and mainly in cells displaying signs of damage.

Active Transport, Cell Nucleus↗
PubMed2003

[Study on the collagen constitution of hyperplastic scar in different ages and its influencing factors].

OBJECTIVE: To investigate the collagen constitution of hyperplastic scar (HS) in different ages and the change of relative factors. METHODS: Thirty cases with HS were divided into two groups according to patients' age: group 1 (1 - 19 years, A) and group 2 (20 - 50 years, B). The normal skin (NS) from corresponding age of volunteers was employed as control group. The changes in TGFbeta1, collagenase (MMP-1) and tissue inhibitor of metalloproteinase (TIMP-1beta) and the collagen ratio were observed by means of in situ hybridization technique and SABC (Strept-Avidin-Biotin complex) immunohistochemistry and image analysis. RESULTS: The ratio of type I to type III collagen in A group was 6.48 in average and 3.76 in B group, but there was no evident difference in the ratio during the disease process in both groups. The expression of TGFbeta1 in A group was much higher than that in B group (P < 0.01). The TIMP-1 mRNA expression showed no difference among all age groups in HS patients, but it was much higher than that in NS group. The MMP-1 expression was evidently lower than TIMP-1 expression, and there was no difference in MMP-1 expression compared with NS group. CONCLUSION: (1) The TGFbeta1 expression in HS patients was negatively correlated with age, and the increased expression of TGFbeta1 produced an increase ratio of type I to type III collagen. (2) High level expression of TIMP-1 led to the formation of HS by inhibiting MMP-1 expression, and the expression was not related to age.

Adolescent↗
PubMed2003

[Neuroprotective effect and mechanisms of hypothermia in neonatal rat cerebral hypoxic-ischemic damages].

OBJECTIVE: Recent studies suggest that hypothermia may be a potential treatment for perinatal hypoxic-ischemic (HI) brain damage. But the mechanisms of this effect are not well known. In the present study, the protective effect of systemic hypothermia as well as effect on apoptosis and associated biochemical events were investigated on neonatal rats with HI brain damage. METHODS: Seven-day-old Wistar rats were subjected to left carotid artery ligation and hypoxia was persisted for 60 min. Immediately at the end of hypoxia, the animals were maintained either at 36 degrees C or 30 degrees C for 10 h at random. Caspase-2, 3 activity in brain homogenate was detected with Western blotting at 24 h post-HI (n = 8 for each group). Immunoactivity of microtubule-associated protein-2 (MAP-2), active caspase-3, apoptosis inducing factor (AIF) and oligonucleotide hairpin probe staining were detected at 72 h post-HI. The infarct volume, neuronal loss in CA(1) sector of hippocampus as well as brain injury scoring were calculated according to MAP-2 staining and hematoxylin and eosin staining. RESULTS: Caspase-2, 3 activities were much higher in the normothermia group [(27.7 +/- 14.7), (94.9 +/- 53.1) pmol/(min.mg protein)] at 24 h post-HI than those of hypothermia [(7.9 +/- 3.4), (21.1 +/- 18.7) pmol/(min.mg protein)] and normal control groups [(7.6 +/- 0.7), (12.9 +/- 0.5) pmol/(min x mg protein)] (P < 0.01). The activities were not significantly different between hypothermia group and normal control group. Western blotting showed that caspase-3 activation process was blocked by hypothermia. The number of active caspase-3 and AIF positive cells in the cortex of ipsilateral hemisphere was much higher in the normothermia group (median: 148.5; 22/field) than that of hypothermia group (median: 48.5; 9/field) (P < 0.05). The number of apoptotic cells as judged by oligonucleotide hairpin probe labeling was much higher in normothermia group (median: 144/field) than that of hypothermia group (median: 133/field) (P < 0.05). The brain injury scoring, infarct volume and neuronal loss in CA(1) area of hippocampus were much less in the hypothermia group [10.4 +/- 2.9; 40.5 +/- 34.8)mm(3); 25.7 +/- 11.5] than that of normothermia group [14.2 +/- 3.5; (73.9 +/- 22.4) mm(3); 37.4 +/- 10.6, P < 0.05]. CONCLUSIONS: Systemic hypothermia for 10 h after hypoxia-ischemia seemed to be effective in reducing brain damage and the mechanism is associated with alteration of apoptotic pathway.

Animals↗