BACKGROUND:cellmarker technology has been widely applied in many studies concerning celltransplantation. Chlormethylbenzamido-1,1-dioctadecyl-3,3,3’3’-tetramethylin-docarbocyamine (CM-DIL) and 4’,6-diamidino-2-phenylindole (DAPI) are commonly used for labeling cells. To our knowledge, there are few reports on comparing the two fluorescent dyes.
OBJECTIVE:To compare the effects of CM-DIL and DAPI on labeling bone marrow mesenchymal stem cells in vitro and in vivo.
METHODS:Isolation and expansion of bone marrow-derived mesenchymal stem cells were performed according to attachment culture. The cells were labeled by CM-DIL and DAPI, respectively. cellviability was assessed via trypan blue exclusion assay. Growth curves of bone marrow-derived mesenchymal stem cells were depicted using MTS assay. The reduction of fluorescent intensity was observed under an inverted fluorescent contrast phase microscope from passage 1 to passage 3 after labeling. Myocardial infarction was induced by left anterior artery ligation in Sprague-Dawley rats. One week later, bone marrow-derived mesenchymal stem cells labeled by CM-DIL or DAPI were injected randomly into the border area of infarct myocardium. After 3 days, transplanted celldistribution was examined under the fluorescent microscope through paraffin sections and frozen sections respectively.
RESULTS AND CONCLUSION:In vitro, bone marrow-derived mesenchymal stem cells labeled by both CM-DIL and DAPI showed decreased cellproliferation during the early period;the percentage of fluorescent-positive cells was approximately 100%in the two groups;however, the fluorescent intensity was significantly reduced from passage 1 to passage 3 in bone marrow-derived mesenchymal stem cells labeled by DAPI. In vivo, the transplanted cells were detected in a concentrated way both on the paraffin sections and frozen ones;the background color of frozen sections was lower in the CM-DIL group than in the DAPI group;false positive results of fluorescent expression could be eliminated in the CM-DIL group by using fluorescent mounting medium with the fluorescence of DNA staining. These data indicates that CM-DIL is more appropriate to in vivo tracing cells than DAPI.

Objective To examine the relationship between gender and intraventricular hemorrhage (IVH) in very low birth weight infants (VLBWI) and extremely low birth weight infants (ELBWI).Methods From January 1,1999 to December 31,2012,data on VLBWI and ELBWI,who were admitted to the neonatal intensive care unit of Yuying Children's Hospital within 14 d after birth,were retrospectively collected.The Chi-square test and t test were used to compare neonatal outcomes between male and female infants.The Logistic model was used to analyze the risk factors for IVH.Results A total of 1 008 cases were enrolled,including 615 males and 393 females,895 VLBWI and 113 ELBWI.The incidence of IVH was 15.1％ (152/1 008) and the incidence of severe IVH was 8.4％ (85/1 008).Compared with females,males had a higher total incidence of IVH [17.2％ (106/615) vs 11.7％ (46/393),x2=5.728,P＜0.05] and severe IVH [9.8％ (60/615) vs 6.4％ (25/393),x2=3.896,P＜0.05].These differences were also seen in VLBWI with a birth weight of 1 250 to 1 499 g [IVH:13.7％ (47/344) vs 7.8％ (17/217),x2=4.473,P=0.034; severe IVH:7.6％ (26/344) vs 2.8％ (6/217),x2=5.684,P=0.017].Logistic regression analysis showed that the risk factors for IVH were as follows:gestational age ＜28 weeks (aOR=2.012,95％CI:1.288-3.143,P＜0.05),neonatal respiratory distress syndrome (aOR=l.584,95％CI:1.007-2.492,P＜0.05),invasive mechanical ventilation (aOR=2.743,95％CI:1.826-4.121,P＜0.05),electrolyte disturbance (aOR=2.128,95％CI:1.092-4.149,P＜0.05) and periventricular leukomalacia (aOR=2.901,95％CI:1.312-6.416,P＜0.05),but not male sex (aOR=1.351,95％CI:0.917-1.991,P=0.128).The risk factors for severe IVH were gestational age ＜28 weeks (aOR=2.200,95％CI:1.305-3.708,P＜0.05),invasive mechanical ventilation (aOR=4.714,95％CI:2.809-7.911,P＜0.05) and electrolyte disturbance (aOR=2.232,95％CI:1.047 4.759,P＜0.05),but not male sex (aOR=1.361,95％CI:0.823 2.252,P=0.247).Conclusions Male VLBWI and ELBWI have a higher incidence of IVH and severe IVH,but male sex is not a risk factor for IVH or severe IVH.

Objective To assess the value of apparent diffusion coefficient (ADC)map with low b-value to monitor the ablated tissue after high-intensity focused ultrasonic (HIFU)treatment for uterine fibroids.Methods 25 patients with 34 uterine fibroids were treated with HIFU.All patients underwent the routine MRI scans (including pre-and post-contrast scanning)and monoexponential model DWI with b values of 150,600 and 1 000 s/mm2 before the surgery and within 24 hours after the surgery.The mean ADC values with different b-values of the ablated and non-ablated tissues between pre-and post-treatment were analyzed by one-way ANOVA test.The consistency of the ablation area between ADC maps with different b-values and contrast enhancement MRI were evaluated. Results With the b-value of 150 s/mm2 ,the mean ADC value of the ablated tissue was (1.48±0.27)×10-3 mm2/s,which was less significantly than that of pre-treatment (2.06±0.21)×10-3 mm2/s and non-ablated tissue (1.98±0.23)×10-3 mm2/s (P<0.05). However,there were no significant differences in ADC values with the b values of 600 s/mm2 and 1 000 s/mm2 among those areas (P>0.05).A fine consistency of the ADC map with the low b-value (150 s/mm2 )was found with non-perfusion volume on contrast-enhanced T1 WI,which was superior to that with high b-values (600 s/mm2 and 1 000 s/mm2 )(P<0.05).Conclusion ADC map with low b-value (150 s/mm2 )can be used to evaluate the blood-supply changes and ablated volume of uterine fibroids indirectly,which helps to assess the treatment effect of HIFU.

Parkinson's disease (PD) is a common age-related neurodegenerative disorder characterized mainly by motor dysfunction resulting in bradykinesia, rigidity, tremor, gait impairment, and postural instability. The classic pathogenic feature of PD is preferential loss of dopaminergic neurons in the substantia nigra. Downregulation of rRNA transcription is one of major mechanisms to maintain cellular homeostasis under stress conditions. Nucleolar stress has emerged as a component of the degenerative process caused by impaired rRNA transcription and altered nucleolar integrity. Recent study has indicated that the response to stress conditions and quality control mechanisms are impaired in PD, and that metabolic stress may be a trigger mechanism for PD. This review aims to present evidence for a role of nucleolar stress in PD and has summarized mechanisms by which nucleolar stress may play a role in the progression of PD.
Cell Nucleolus ; physiology ; Humans ; Parkinson Disease ; etiology ; physiopathology ; RNA, Ribosomal ; genetics ; Signal Transduction ; Stress, Physiological ; TOR Serine-Threonine Kinases ; physiology

BACKGROUND:Our previous experimental results have shown that hyaluronic acid hydrogel can act as a vehicle for bone marrow mesenchymal stem cell delivery to improve the cardiac function of rats with myocardial infarction. OBJECTIVE:To explore the molecular mechanism of bone marrow mesenchymal stem cells and hyaluronic acid hydrogel in promoting damaged heart repair. METHODS:Bone marrow mesenchymal stem cells from male Sprague-Dawley rats were isolated and cultured,and then hyaluronic acid-encapsulated bone marrow mesenchymal stem cells were cultured in vitro in a three-dimensional manner.A model of myocardial infarction was made by ligating the left anterior descending artery of female Sprague-Dawley rats.After 1 week,the model rats were screened by ultrasonic testing and then eligible ones were randomly divided into four groups:PBS group(n=12),hyaluronic acid group(n=12),bone marrow mesenchymal stem cell group(n=15),and hyaluronic acid-encapsulated bone marrow mesenchymal stem cell group(n=15).At 1 week after ligation,the model rats underwent the secondary thoracotomy followed by corresponding injections into the infarcted region and its marginal zone.The expression levels of matrix metalloproteinase-2,vascular endothelial growth factor,thymosin β4 and c-Kit were examined at post-injection day 1,week 1 and week 2 by western blot assay.At post-injection week 2,immunofluorescence staining was used to detect the differentiation of transplanted cells. RESULTS AND CONCLUSION:(1)The expression levels of matrix metalloproteinase-2 and vascular endothelial growth factor protein in the infarct zone in the bone marrow mesenchymal stem cell group were significantly up-regulated at week 1 compared with the other three groups(P<0.05).At week 2,the hyaluronic acid group had a lower expression of matrix metalloproteinase-2 and vascular endothelial growth factor protein than the other three groups(P<0.05).However,the expression of matrix metalloproteinase-2 and vascular endothelial growth factor protein in the hyaluronic acid+bone marrow mesenchymal stem cell group was not significantly different compared with the bone marrow mesenchymal stem cell group.This was primarily attributable to a prolonged paracrine effect via the controlled release of the hyaluronic acid hydrogel.This prolonged paracrine effect offsets the inhibitory effect induced by hyaluronic acid hydrogel at 2 weeks.(2)Compared with the PBS group,thymosin β4 and c-Kit expression levels in the hyaluronic acid group,bone marrow mesenchymal stem cell group and bone marrow mesenchymal stem cell+hyaluronic acid group were significantly increased(P<0.05).(3)No differentiation of transplanted cells into cardiomyocytes or blood vessels was detected 2 weeks after transplantation.(4)It is indicated that transplanted bone marrow mesenchymal stem cells promote myocardial repair through the paracrine effect,and hyaluronic acid hydrogel prolongs the paracrine effect of transplanted bone marrow mesenchymal stem cells.

Objective: To investigate the role of p75 neurotrophin receptor (p75NTR) in the irradiation-induced hippocampal neurogenesis impairment. Methods: Thirty Sprague-Dawley rats were subject to whole brain irradiation with a single dose of 10 Gy 4 MeV electron beam. At 1 month after irradiation, the hippocampal tissues of the rats were collected. Western blot was used to detect the changes in the expression level of p75NTR protein. Immunofluorescence confocal laser microscopy was performed to observe the variations in the hippocampal neurogenesis. The stereotatic method was adopted for intra-hippocampal injection of AAV-shp75NTR to specifically knock out p75NTR.The relationship between p75NTR and hippocampal neurogenesis was analyzed. Results: Western blot demonstrated that the expression of p75NTR protein was significantly up-regulated by 43.8% after irradiation (P<0.05). Immunofluorescent staining showed that the quantity of BrdU⁺ NeuN⁺ cells in rats was significantly decreased by 81.5% at 1 month after irradiation compared with that in the control group (P<0.01). After the specific knockout of p75NTR, hippocampal neurogenesis was obviously protected. Conclusion p75NTR plays a pivotal role in the irradiation-induced hippocampal neurogenesis impairment.