Experimental study on repairing skin defect by tissue-engineered skin substitute compositely constructed by adipose-derived stem cells and fibrin gel

OBJECTIVE

To study the application value of artificial skin substitute compositely constructed by adipose-derived stem cells and fibrin gel in skin defect.

MATERIALS AND METHODS

Adipose-derived stem cells (ADSCs) were obtained from healthy pure green fluorescent protein (GFP) transgenic mice and were proved to have multiple differentiation potentials. They compositely constructed artificial skin substitute in vitro with fibrin gel. 24 SD rats of either gender, with the gestational age of 3-5 weeks, were divided into four groups in the experiment, namely model group (autologous skin flap transplantation), adipose-derived stem cell transplantation group, fibrin gel transplantation group and compound transplantation group, 6 rats for each group. At the skin blood flow (measured by applying laser Doppler rheometer) and survival rate of the flap on 7d and 21d respectively, the materials were transplanted at back skin injury (1 cm×1 cm) to prepare tissue slice for routine HE staining. The conditions of wound healing were observed, and the angiogenesis of flap neovascularization was detected by the immunofluorescent assay.

RESULTS

The skin blood flow, the survival rate of flap and density of neovascularization 7d and 21d after transplantation were significantly higher than those of stem cell group, followed by the model group, with the lowest ones in the fibrin gel group. The differences had statistical significance (p<0.05). The wound healing time of compound group was significantly shorter than that of stem cell group, followed by the model group, with the longest one in the fibrin gel group. The differences had statistical significance (p<0.05).

CONCLUSIONS

The artificial skin substitute compositely constructed by adipose-derived stem cells and fibrin gel could significantly shorten healing time and improve the survival rate of the flap in skin defect, with better application value.

Neutron Generation by Laser-Driven Spherically Convergent Plasma Fusion

We investigate a new laser-driven spherically convergent plasma fusion scheme (SCPF) that can produce thermonuclear neutrons stably and efficiently. In the SCPF scheme, laser beams of nanosecond pulse duration and 10^{14}-10^{15}  W/cm^{2} intensity uniformly irradiate the fuel layer lined inside a spherical hohlraum. The fuel layer is ablated and heated to expand inwards. Eventually, the hot fuel plasmas converge, collide, merge, and stagnate at the central region, converting most of their kinetic energy to internal energy, forming a thermonuclear fusion fireball. With the assumptions of steady ablation and adiabatic expansion, we theoretically predict the neutron yield Y_{n} to be related to the laser energy E_{L}, the hohlraum radius R_{h}, and the pulse duration τ through a scaling law of Y_{n}∝(E_{L}/R_{h}^{1.2}τ^{0.2})^{2.5}. We have done experiments at the ShengGuangIII-prototype facility to demonstrate the principle of the SCPF scheme. Some important implications are discussed.

[Efficacy and safety of tertiary hospital guided and community-driven family self-help cardiac rehabilitation model]

Objective: To explore the efficacy and safety of tertiary hospital guided and community-driven family self-help cardiac rehabilitation model. Methods: This study was a prospective randomized controlled study, 80 patients from Beijing Electrical Power Hospital and Beijing Jingmei Group General Hospital with acute coronary syndrome were included from June to December 2015 and divided into 2 groups. Patients in rehabilitation group (n=52) received tertiary hospital(Peiking University Peoples' Hospital) guided and community-driven family self-help cardiac rehabilitation for 3 months, and patients in control group (n=28) received routine secondary treatment for 3 months. Following parameters including 6 minutes walk distance, score of life quality (evaluated by Short Form-12), score of anxiety (evaluated by Generalized Anxiety Disorder-7), score of depression (evaluated by Perceived Health Questionnaire-9), self-management competency (evaluated by questionnaire) were collected at baseline and after treatment for 3 months. Results: Compared with control group, 6 minutes walk distance was longer in rehabilitation group((60.2±6.8) meters vs. (24.9±10.5)meters, P<0.01). The difference values between after and before intervention of life quality scores((0.14±3.90)scores vs.(-7.44±5.85)scores, P>0.05), anxiety scores((-0.16±2.12 ) scores vs.(0.70±1.13)scores, P>0.05) and depression scores((-1.17±2.79) scores vs.(0.60±0.36)scores, P>0.05) were similar between the 2 groups. The amplification of patients with regular exercise (50.26% vs. 0, P<0.05), limit sugary foods usually and always (53.22% vs. 3.98%, P<0.05), eat 200-400 g fruits usually and always (78.61 % vs. 0, P<0.05), eat 300-500 g vegetables usually and always (9.74% vs. 0, P<0.05), and answering very confident to questions such as let the physicians know about your diseases (40.17% vs. 5.00%, P<0.05), know how to take medicines (44.52% vs. 5.00%, P<0.05), know how much exercise was right for yourself (26.43% vs.0, P<0.05) were significantly higher in rehabilitation group than in control group. There were no cardiac rehabilitation training related cardiovascular events. Conclusion: Tertiary hospital guided and community-driven family self-help cardiac rehabilitation model is an effective and safe management model of cardiovascular disease in chronic phase, and it is necessary to further expand the study population to verify the efficacy of this model.

Prostaglandin E2 regulates renal function in C57/BL6 mouse with 5/6 nephrectomy

AIMS

To investigate the roles of cyclooxygenases (COX) and their metabolites in C57/BL6 mice with 5/6 nephrectomy, an animal model of chronic renal failure.

MAIN METHODS

C57/BL6 mice were grouped into sham-operated (2K), one kidney removal (1K) and 5/6 nephrectomy groups (5/6Nx). Renal resistive index was measured by ultrasonography. Blood, aortae, renal arteries and renal cortex were collected for measurement of kidney function, assessment of vascular responsiveness, Western blotting, immuohistochemistry and enzyme-linked immunosorbent assays.

KEY FINDINGS

After four weeks, acetylcholine-induced relaxations were blunted in renal arteries of 1K and 5/6Nx mice; indomethacin, a non-selective COX inhibitor, improved the response in 5/6Nx, but not in 1K renal arteries. In 5/6Nx renal arteries, but not in 1K preparations, the protein presence of endothelial nitric oxide synthase (eNOS) was decreased, while that of COX-2 and its products [prostacyclin and thromboxane A₂] were increased. The renal resistive index was lower in 5/6Nx mice, suggesting a lower resistance in the renal microvasculature. In the renal cortex of 5/6Nx mice, eNOS protein presence was increased; while the presence of COX-2 was not detectable. The prostaglandin E₂ level was lower in the 5/6Nx cortex than in the other two groups.

SIGNIFICANCE

The early stage of renal mass removal is associated with increased renal arterial constriction and reduced microvascular resistance. The former is due to downregulation of eNOS and upregulation of COX-2, leading to an increased production of prostacyclin and thromboxane A₂. A reduced production of PGE₂ in the renal cortex is important for maintaining normal renal function.

Neural stem/progenitor cells on collagen with anchored basic fibroblast growth factor as potential natural nerve conduits for facial nerve regeneration

Introducing neural stem/progenitor cells (NS/PCs) for repairing facial nerve injuries could be an alternative strategy for nerve gap reconstruction. However, the lack of success associated with current methods of applying NS/PCs to neurological disease is due to poor engraftment following transplantation into the host tissue. In this work, we developed rat-tail collagen-based nerve conduits to repair lengthy facial nerve defects, promoting NS/PC proliferation in the natural nerve conduits with anchored bFGF to improve the therapeutic effects of cell transplantation. In vitro studies showed that heparinized collagen prevented leakage of bFGF and NS/PCs expended in the rat-tail collagen gel with the anchored bFGF. The natural nerve conduits were implanted to connect 8-mm facial nerve defects in rats. The repair outcomes including vibrissae movements, electrophysiological tests, immunohistochemistry and remyelination analysis of regenerated nerve were evaluated. At 12weeks after implantation, only natural nerve conduits treated group showed Hoechst labeled NS/PCs. Besides, the natural nerve conduit significantly promoted functional recovery and nerve growth, which was similar to those of the gold standard, an autograft. The animal experiment results suggesting that the natural nerve conduits were valuable for facial nerve reconstruction.

STATEMENT OF SIGNIFICANCE

Neural stem/progenitor cells (NS/PCs) were beneficial for the treatment of nervous system diseases. However, after transplantation, the beneficial was limited because the number of living NS/PCs decreased rapidly due to insufficient signaling molecules, such as growth factors, in the microenvironments surrounding transplanted cells. In the present study, we constructed collagen-based nerve conduit with anchored bFGF to achieve higher numbers of NS/PCs for repairing facial nerve injury. Compared with other methods involving neutral salt treatment or dialysis, the fabrication method of collagen scaffolds was simple, low-cost and safe, requiring a relatively short time to prepare. At 12weeks after transplantation, the functional and histological results of natural nerve conduits treated group showed significant similarities to the gold standard method of nerve autografting.

Interfacial rheology of coexisting solid and fluid monolayers

Biologically relevant monolayer and bilayer films often consist of micron-scale high viscosity domains in a continuous low viscosity matrix. Here we show that this morphology can cause the overall monolayer fluidity to vary by orders of magnitude over a limited range of monolayer compositions. Modeling the system as a two-dimensional suspension in analogy with classic three-dimensional suspensions of hard spheres in a liquid solvent explains the rheological data with no adjustable parameters. In monolayers with ordered, highly viscous domains dispersed in a continuous low viscosity matrix, the surface viscosity increases as a power law with the area fraction of viscous domains. Changing the phase of the continuous matrix from a disordered fluid phase to a more ordered, condensed phase dramatically changes the overall monolayer viscosity. Small changes in the domain density and/or continuous matrix composition can alter the monolayer viscosity by orders of magnitude.

[Analysis of the therapeutic effects of different treatment modalities on the outcomes of 87 patients with lung oligometastasis from nasopharyngeal carcinoma after radiotherapy]

OBJECTIVE

The aim of the present study was to evaluate the efficacy of three different modalities in treatment of lung oligometastases from nasopharyngeal carcinoma (NPC) after radiotherapy and to identify a more appropriate treatment modality.

METHODS

The clinical data of 87 cases of lung oligometastases from NPC were analyzed retrospectively. Among them, 33 patients underwent local small-field irradiation+ /- chemotherapy, 28 underwent whole-lung irradiation+ chemotherapy, and 26 underwent simple chemotherapy. The survival rates were calculated using Kaplan-Meier analysis. The differences among the modalities were evaluated using the log-rank test. Cox univariate and multivariate analyses were performed to determine the influencing factors.

RESULTS

The 3-year lung metastasis survival (LMS) rates of patients with lung metastasis undergoing the three treatment modalities (local small-field irradiation+ /-chemotherapy, whole-lung irradiation+ chemotherapy and chemotherapy alone) were 89.3%, 72.7%, and 72.4%, respectively, showing a significant difference between the groups (P=0.003). Further subgroup analysis showed that the 5-year LMS rate was significantly higher in the local small-field irradiation+ /-chemotherapy group than that in the whole-lung irradiation+ chemotherapy group and chemotherapy alone group (P=0.001). The 2-year progression-free survival (PFS) rates of the three groups were 57.1%, 25.8% and 3.8%, respectively, showing significant intergroup differences (P=0.002 and P<0.001). Multivariate analysis indicated that compared with the whole lung irradiation group and the chemotherapy alone group, the local irradiation+ /- chemotherapy is an independent favorable prognostic factor for LMS and PFS (P<0.05).

CONCLUSION

Local radiotherapy combined with systemic chemotherapy is the best therapeutic modality for lung oligometastases derived from NPC after radiotherapy, improving the LMS and prolonging the PFS.

Identification and characterization of cell-bound membrane vesicles

In contrast to the released/circulating membrane vesicles (extracellular vesicles), cell-bound membrane vesicles are poorly identified and characterized. In this study, cell-bound membrane vesicles on human umbilical vein endothelial cells (HUVECs) and human hepatoma HepG-2 cells were investigated. We identified that cell-bound membrane vesicles are not co-localized with the major markers for extracellular vesicles (e.g. phosphatidylserine, CD63, CD107α, CD31, and DNA fragments for the three well-known types of extracellular vesicles) and for intracellular organelles with similar sizes (e.g. MitoTracker and LAMP1/LAMP3 for mitochondria and multivesicular bodies or lysosomes, respectively). The data imply that cell-bound membrane vesicles are neither the precursors of extracellular vesicles nor a false structure pushed up by an intracellular organelle but probably a novel unknown structure in the plasma membrane. Moreover, we revealed that cell-bound membrane vesicles are resistant to various detergents including but probably not limited to Triton X-100, SDS, and saponin. We further characterized that these unique vesicles are soluble in organic solvents (e.g. chloroform-methanol mixture and ethanol) which can be prevented by a lipid-stabilizing fixative (e.g. OsO₄) and that they are co-localized with, but do not monopolize, the major markers (e.g. caveolin-1 and GM1) for lipid rafts (a nano-sized detergent-resistant domains in the plasma membrane). The data imply that cell-bound membrane vesicles contain the lipid component and lipid rafts. Involvement of other specific unknown components might explain the detergent resistance of cell-bound membrane vesicles. Further research will mainly depend on the establishment of an effective approach for isolation/purification of these vesicles from the plasma membrane.

[Prognostic factors of patients with T3N0M0 renal cell carcinoma: a single-center retrospective study of 182 patients]

OBJECTIVE

To evaluate the impacts of clinical, pathological, and laboratory factors on oncological outcomes of patients with T3N0M0 renal cell carcinoma.

METHODS

The clinical data, laboratory exam results, and follow-up outcomes of 182 patients with T3N0M0 renal cell carcinoma who underwent nephrectomy from 2007 to 2012 in Peking University First Hospital were retrospectively collected. The 5-year cancer-specific survival and 5-year recurrence-free survival of all the patients were calculated using Kaplan-Meier method, and the statistical significance between the survival curves were compared using the Log-rank test. Variables with significant differences in the univariate analysis were subjected to the multivariate analysis by Cox regression model. All the comparisons were conducted using two-tailed test and P<0.05 was considered statistically significant.

RESULTS

A total of 182 patients were included in this study. Of all the 182 patients, 126 were male (69.23%) and 56 were female (30.77%). The mean age was (56.75±12.45) years. The median follow-up time was 48 months (3-99 months). At the end of the follow-up, 50 patients (27.47%) died due to the disease after a median of 29.74 months and 59 patients (32.42%) had tumor recurrence after a median of 22.12 months. The 5-year cancer-specific survival of all patients was 68.30% (95% CI: 60.16%-75.84%); the 5-year recurrence-free survival was 60.70% (95% CI: 53.16%-68.84%). In the univariate analysis, diabetes mellitus, tumor invasion status, Fuhrman grade, serum album, serum cholestenone, anemia, and neutrophils percentage were associated with the cancer-specific survival and Fuhrman grade, serum album and anemia were associated with the recurrence-free survival. Variables with significant differences on univariate analysis were included in Cox multivariate regression analysis. Multivariate Logistic regression analysis showed that diabetes mellitus (HR=2.434, 95% CI: 1.243-4.769, P=0.010), hypoalbuminemia (HR=2.188, 95% CI: 1.074-1.074, P=0.031), and anemia (HR=3.320, 95% CI: 1.839-5.991, P<0.001) were independent risk factors significantly associated with cancer-specific survival; and higher Fuhrman grade (HR=2.552, 95% CI: 1.433-4.545, P=0.001), anemia (HR=2.535, 95% CI: 1.497-4.293, P=0.001) were independent factors significantly associated with recurrence-free survival.

CONCLUSION

Diabetes mellitus, hypoalbuminemia, and anemia were independent risk factors significantly associated with cancer-specific survival of T3N0M0 renal cell carcinoma patients; higher Fuhrman grade and anemia were independent risk factors significantly associated with tumor recurrence of T3N0M0 renal cell carcinoma patients.

MicroRNA-382 inhibits prostate cancer cell proliferation and metastasis through targeting COUP-TFII

MicroRNAs (miRNAs) have emerged as important regulators in cancer that are implicated in regulation of various cellular processes. miR-382 has been proposed as a tumor suppressor by several recent studies. However, the function of miR-382 in prostate cancer remains unknown. In this study, we aimed to investigate the potential function of miR-382 in prostate cancer. We found that miR-382 was significantly decreased in prostate cancer specimens and cancer cell lines. The overexpression of miR-382 in prostate cancer cells markedly inhibited cell proliferation, migration, and invasion. In contrast, miR-382 suppression exhibited an opposite effect. Target analysis predicted that chicken ovalbumin upstream promoter transcription factor II (COUP‑TFII) was a direct target of miR-382. This prediction was experimentally confirmed by dual-luciferase reporter assay, real-time quantitative polymerase chain reaction, and western blot analysis. Our results further demonstrated that miR-382 inhibited the downstream genes of COUP‑TFII, including Snail and matrix metalloproteinase 2 (MMP2). Moreover, the restoration of COUP‑TFII expression significantly blocked the inhibitory effect of miR-382 on cell proliferation, migration, and invasion, and Snail expression. Taken together, this study suggests that miR-382 inhibits prostate cancer cell proliferation and metastasis through inhibiting COUP‑TFII, representing an important new mechanism for understanding prostate cancer pathogenesis and providing a novel therapeutic candidate target for prostate cancer therapy.

[Methylation status of RASSF1A gene promoter in upper tract urothelial carcinoma and its clinical significance]

OBJECTIVE

To investigate the methylation status of the RASSF1A gene promoter in upper tract urothelial carcinoma (UTUC) tissues and its correlation with clinicopathologic characteristics and postoperative recurrence of primary UTUC.

METHODS

In a retrospective design, a total of 687 patients who underwent surgeries for primary UTUC in the urology department of Peking University First Hospital were enrolled. The methylation status of the RASSF1A gene promoter was analyzed using methylation-sensitive polymerase chain reaction on tumor specimens.

RESULTS

Aberrant methylation for the RASSF1A gene promoter was detected in 183 (26.6%) DNA samples in total. Aberrant methylation of the RASSF1A gene was strongly associated with tobacco consumption (P=0.044), ipsilateral hydronephrosis (P<0.001 ), tumor location (P<0.001 ), tumor stage (P=0.001), tumor grade (P=0.007), lymph node metastasis (P=0.001) and growth pattern (P=0.013). The methylated RASSF1A gene promoter was an independent risk factor for bladder recurrence (P<0.001, HR=0.471) and contralateral recurrence (P=0.030, HR=0.269) of UTUC after surgery. Hypermethylated RASSF1A was predictive for improved bladder recurrence-free survival (BRFS) (P<0.001) and contralateral recurrence-free survival (CRFS) (P=0.021) in the UTUC patients. Compared with the patients with unmethylated RASSF1A, the patients containing tumors with hypermethylated RASSF1A had tendency toward longer recurrence-free survival time [(114.4±3.9) months vs. (84.0±3.2) months for BRFS, (138.1±1.8) months vs. (132.9±1.9) months for CRFS] and higher estimated cumulative recurrence-free survive rates ( five-year survival rate for example, 79.8%±3.4% vs. 57.4%±2.6% for BRFS, 98.9%±0.8% vs. 93.0%±1.4% for CRFS). Additionally, tumor multifocality (P=0.002, HR=1.538), and ureteroscopy before surgery (P=0.001, HR=1.725) were independent risk factors for bladder recurrence in postoperative UTUC patients.

CONCLUSION

The methylation status of the RASSF1A gene promoter appears to be a promising epigenomic biomarker for assessing the aggressiveness of UTUC and a predictor predicting the urinary tract recurrence after surgery.

Preoperative ropivacaine with or without tramadol for femoral nerve block in total knee arthroplasty

PURPOSE

To compare the analgesic effect of preoperative ropivacaine with or without tramadol for femoral nerve block in total knee arthroplasty (TKA).

METHODS

14 men and 46 women aged 59 to 80 years who were American Society of Anesthesiologists (ASA) grade I or II and were scheduled for TKA were randomised to receive preoperative femoral nerve block with 20 ml of 0.375% ropivacaine plus tramadol 0 mg (n=15), 50 mg (n=15), or 100 mg (n=15), or no preoperative femoral nerve block (control) [n=15]. Femoral nerve block was performed by a single anaesthesiologist before the standardised combined spinal epidural anaesthesia. Postoperatively, patientcontrolled analgesia was given. The visual analogue score (VAS) for pain at rest and on movement was recorded at 8, 12, 24, 48, and 72 hours. Passive knee range of motion (ROM) was measured at 24, 48, and 72 hours.

RESULTS

The 4 groups were comparable in terms of age, gender, weight, ASA grade, and operating time. Compared with patients who received no femoral nerve block or ropivacaine alone, those who received femoral nerve block with 20 ml of 0.375% ropivacaine plus tramadol 50 mg or 100 mg recorded a lower VAS for pain at rest and on movement at 8 to 72 hours, longer sensory and motor block time, and lower demand, delivery, and total amount of patientcontrolled analgesia. The passive knee ROM at 24 to 72 hours was greater in patients with femoral nerve block than in those without.

CONCLUSION

Preoperative femoral nerve block with 20 ml of 0.375% ropivacaine and 100 mg tramadol resulted in the best analgesic effect.

Identification of Natural Infections in Sheep/Goats with HoBi-like Pestiviruses in China

The natural infections of HoBi-like pestiviruses in cattle have been reported in South America, Europe and Asia. In China, although the detections of HoBi-like pestivirus have been reported, the epidemiological investigation was limited. From January 2014 to October 2015, several flocks of sheep/goats in Henan province in central China suffered respiratory diseases which were recovered slowly after antibiotics treatment. To test whether it is the HoBi-like pestivirus caused this symptom, 49 serum samples and 22 nasal swabs were then collected for analysis by serology and RT-PCR. Serological result revealed that prevalence of pestivirus in small ruminants was 12.2% (6/49) in central China. Sequence analysis of partial 5'-UTR nucleotides of pestivirus-positive samples suggested that HoBi-like pestivirus might have circulated in sheep/goats of China for a period and have evolved into new genotype clusters. It is apparent that the study provides the molecular evidence of natural infections in goat/sheep species with HoBi-like pestiviruses in China.

eNOS gene T786C, G894T and 4a4b polymorphisms and male infertility susceptibility: a meta-analysis

The association between polymorphism of eNOS and male infertility in several studies was controversial. To explore a more precise estimation of the association, a meta-analysis of eight case-control studies, including 1,968 cases and 1,539 controls, were selected. The meta-analysis was conducted by calculating the pooled odds ratio (OR) with a 95% confidence interval (95% CI). Overall, the association between T786C and risk of male infertility was obvious (TC vs. TT: OR, 1.20; 95% CI, 1.01-1.42; CC vs. TT: OR, 3.37; 95% CI, 1.65-6.87; TC/CC vs. TT: OR, 1.47; 95% CI, 1.25-1.73; CC vs.

TT/TC

OR, 3.18; 95% CI, 1.54-6.56; TC vs. TT: OR, 1.65; 95% CI, 1.27-2.03). However, no overall association was observed between the other two polymorphisms of eNOS (G894T and 4a4b) and male infertility. Stratified analysis showed that significantly strong association between T786C polymorphism and semen quality was present in all three types of male infertility (azoospermia, oligozoospermia and asthenozoospermia). In the subgroup analysis based on ethnicity, both T786C and 4a4b could influence the risk of male infertility in Asian and Caucasian. Further studies of polymorphisms of eNOS with their biological functions are needed to understand the role in the development of male infertility.

Evaluation of tumour vascular distribution and function using immunohistochemistry and BOLD fMRI with carbogen inhalation

AIM

To evaluate oxygenation changes in rat subcutaneous C6 gliomas using blood-oxygen-level dependent (BOLD) functional magnetic resonance imaging (fMRI) combined with non-haemodynamic response function (non-HRF) analysis.

MATERIALS AND METHODS

BOLD fMRI were performed during carbogen inhalation in 20 Wistar rats bearing gliomas. Statistical maps of spatial oxygenation changes were computed by a dedicated non-HRF analysis algorithm. Three types of regions of interest (ROIs) were defined: (1) maximum re-oxygenation zone (ROI_max), (2) re-oxygenation zones that were less than the maximum re-oxygenation (ROI_non-max), and (3) zones without significant re-oxygenation (ROI_none). The values of percent BOLD signal change (PSC), percent enhancement (ΔSI), and significant re-oxygenation (T) were extracted from each ROI. Tumours were sectioned for histology using the fMRI scan orientation and were stained with haematoxylin and eosin and CD105. The number of microvessels (MVN) in each ROI was counted. Differences and correlations among the values for T, PSC, ΔSI, and MVN were determined.

RESULTS

After carbogen inhalation, the PSC significantly increased in the ROI_max areas (p<0.01) located in the tumour parenchyma. No changes occurred in any of the ROI_none areas (20/20). Some changes occurred in a minority of the ROI_non-max areas (3/60) corresponding to tumour necrosis. MVN and PSC (R=0.59, p=0.01) were significantly correlated in the ROI_max areas. In the ROI_non-max areas, MVN was significantly correlated with PSC (R=0.55, p=0.00) and ΔSI (R=0.37, p=0.00).

CONCLUSIONS

Statistical maps obtained via BOLD fMRI with non-HRF analysis can assess the re-oxygenation of gliomas.

The Grooved Rodent Incisor Recapitulates Rudimentary Teeth Characteristics of Ancestral Mammals

It is known from the paleontology studies of eutherian mammals that incisor numbers were reduced during evolution. The evolutionary lost incisors may remain as vestigial structures at embryonic stages. The recapitulation of the incisor patterns among mammalian species will potentially uncover the mechanisms underlying the phenotypic transition of incisors during evolution. Here, we showed that a minute tooth formed in the presumptive groove region of the gerbil upper incisor at the early developmental stages, during which multiple epithelial swellings and Shh transcription domains spatiotemporally appeared in the dental epithelium, suggests the existence of vestigial dental primordia. Interestingly, when we trimmed the surrounding mesenchyme from incisor tooth germs at or before the bud stage prior to ex vivo culture, the explants developed different incisor phenotypes ranging from triplicated incisors, duplicated incisors, to Lagomorpha-like incisors, corresponding to the incisor patterns in the eutherian mammals. These results imply that the phenotypic transition of incisors during evolution, as well as the achievement of ultimate incisors in adults, arose from differential integrations of primordia. However, when the incisor tooth germ was trimmed at the cap stage, a grooved incisor developed similar to the normal condition. Furthermore, the incisor tooth germ developed a small but smooth incisor after the additional removal of the minute tooth and a lateral rudiment. These results suggest that multiple dental primordia integrated before the cap stage, with the labial primordia contributing to the labial face of the functional incisor. The minute tooth that occupied the boundary of the 2 labial primordia might be implicated in the groove formation. This study sheds light on how rudiments incorporate into functional organs and aids the understanding of incisor evolution.

[Methylation status of RASSF1A gene promoter in upper tract urothelial carcinoma and its clinical significance]

OBJECTIVE

To investigate the methylation status of the RASSF1A gene promoter in upper tract urothelial carcinoma (UTUC) tissues and its correlation with clinicopathologic characteristics and postoperative recurrence of primary UTUC.

METHODS

In a retrospective design, a total of 687 patients who underwent surgeries for primary UTUC in the urology department of Peking University First Hospital were enrolled. The methylation status of the RASSF1A gene promoter was analyzed using methylation-sensitive polymerase chain reaction on tumor specimens.

RESULTS

Aberrant methylation for the RASSF1A gene promoter was detected in 183 (26.6%) DNA samples in total. Aberrant methylation of the RASSF1A gene was strongly associated with tobacco consumption (P=0.044), ipsilateral hydronephrosis (P<0.001 ), tumor location (P<0.001 ), tumor stage (P=0.001), tumor grade (P=0.007), lymph node metastasis (P=0.001) and growth pattern (P=0.013). The methylated RASSF1A gene promoter was an independent risk factor for bladder recurrence (P<0.001, HR=0.471) and contralateral recurrence (P=0.030, HR=0.269) of UTUC after surgery. Hypermethylated RASSF1A was predictive for improved bladder recurrence-free survival (BRFS) (P<0.001) and contralateral recurrence-free survival (CRFS) (P=0.021) in the UTUC patients. Compared with the patients with unmethylated RASSF1A, the patients containing tumors with hypermethylated RASSF1A had tendency toward longer recurrence-free survival time [(114.4±3.9) months vs. (84.0±3.2) months for BRFS, (138.1±1.8) months vs. (132.9±1.9) months for CRFS] and higher estimated cumulative recurrence-free survive rates ( five-year survival rate for example, 79.8%±3.4% vs. 57.4%±2.6% for BRFS, 98.9%±0.8% vs. 93.0%±1.4% for CRFS). Additionally, tumor multifocality (P=0.002, HR=1.538), and ureteroscopy before surgery (P=0.001, HR=1.725) were independent risk factors for bladder recurrence in postoperative UTUC patients.

CONCLUSION

The methylation status of the RASSF1A gene promoter appears to be a promising epigenomic biomarker for assessing the aggressiveness of UTUC and a predictor predicting the urinary tract recurrence after surgery.

Transplantation of human induced cerebellar granular-like cells improves motor functions in a novel mouse model of cerebellar ataxia

Stem cell-based reparative approaches have been applied to cerebellum-related disorders during the last two decades. Direct lineage reprogramming of human fibroblasts into functional granular neurons holds great promise for biomedical applications such as cerebellum regeneration and cellbased disease modeling. In the present study, we showed that a combination of Ascl1, Sox2 and OCT4, in a culture subsequently treated with secreted factors (BMP4, Wnt3a and FGF8b), was capable of converting human fibroblasts from the scalp tissue of patients with traumatic brain injury (TBI) into functional human induced cerebellar granular-like cells (hiCGCs). Morphological analysis, immunocytochemistry, gene expression and electrophysiological analysis were performed to identify the similarity of induced neuronal cells to human cerebellum granular cells. Our strategy improved the efficiency for hiCGCs induction, which gave the highest conversion efficiency 12.30±0.88%, and Ath1(+)/Tuj1(+) double positive cells to 5.56±0.80%. We transplanted hiCGCs into the cerebellum of Nmyc(TRE/TRE): tTS mice, a novel mouse model of cerebellar ataxia, and demonstrated that the hiCGCs were able to survive, migrate, proliferate and promote mild functional recovery after been grafted into cerebellum.