[Effects of local transplantation of autologous adipose-derived mesenchymal stem cells on the formation of hyperplastic scar on rabbit ears].

Objective: To investigate the effects of local transplantation of autologous adipose-derived mesenchymal stem cells (ADSCs) on the formation of hyperplastic scar on rabbit ears. Methods: ADSCs were isolated from inguinal fat of six New Zealand rabbits and then sub-cultured. ADSCs of the third passage of each rabbit were used in the following experiments. Six full-thickness skin defect wounds with diameter of 6 mm on the ventral surface of every rabbit ear were made. Wound healing and local-tissue proliferation were observed, and complete epithelization time of wounds and formation time of hyperplastic scar were recorded. The wounds on left ears were selected as group ADSCs, and the wounds on right ears were selected as control group, with 36 wounds in each group. After the complete epithelization of wounds (post injury day 25), 0.2 mL bromodeoxyuridine (BrdU) labeled autologous ADSCs with the concentration of 5×106 per milliliter were injected into each wound of the rabbit of group ADSCs, while the same amount of phosphate buffer solution was injected into each wound of the rabbit of control group. The frequency of injection was once every 5 days, totally for 3 times, and the latter 2 times were injected into scars generated from healed wound. Hyperplastic scars of rabbits of two groups were harvested on the fifth day after the third injection, then the morphology was observed by HE staining, and the arrangement of collagen in hyperplastic scar was observed by VG staining. The distribution of BrdU-labeled ADSCs in the hyperplastic scar was observed with fluorescence microscope. The protein content of type Ⅰ collagen, type Ⅲ collagen, transforming growth factor ß1 (TGF-ß1), and decorin in hyperplastic scar were detected by enzyme-linked immunosorbent assay, and the mRNA expression of decorin and TGF-ß1 in hyperplastic scar were tested by real-time fluorescent quantitative reverse transcription-polymerase chain reaction. Data were processed with paired t test. Results: (1) The complete epithelization time of wounds of rabbits' ears was (20.0±2.0) d post injury, and hyperplastic scars were formed on post injury day 35.0±2.2. On post injury day 40, hyperplastic scars of rabbits of control group were still obvious, while those of group ADSCs became smaller, flat, soft, and light colored. (2) Compared with those in control group, epithelial cell layers and the number of nucleated cells in corium layer of hyperplastic scars of rabbits of group ADSCs were increased, and epithelium foot like and dermal papilla like structures were observed. The collagen density of hyperplastic scars of rabbits of control group was tight and arranged disorderly, while that of group ADSCs were decreased significantly and arranged regularly as compared with that of control group. (3) On post injury day 40, BrdU-labeled ADSCs were still observed in the hyperplastic scars of rabbits of group ADSCs. (4) The protein content of type Ⅰ collagen, type Ⅲ collagen, TGF-ß1, and decorin in hyperplastic scars of rabbits of group ADSCs were respectively (1.40±0.04) and (8.18±0.23) µg/L, (25.1±0.7) ng/L, and (4.872±0.101) ng/mL, and those in hyperplastic scars of rabbits of control group were respectively (2.29±0.05) and (12.20±0.38) µg/L, (37.2±1.1) ng/L, and (4.143±0.024) ng/mL. Compared with those in control group, the protein content of type Ⅰ collagen, type Ⅲ collagen, and TGF-ß1 in hyperplastic scars of rabbit of group ADSCs were significantly decreased (with t values from -33.66 to -22.84, P values below 0.001), while the protein content of decorin were significantly increased (t=10.41, P<0.001). (5) Compared with those in control group, the mRNA expression of TGF-ß1 in hyperplastic scars of rabbits of group ADSCs was significantly decreased (t=4.45, P<0.01), while the mRNA expression of decorin was significantly increased (t=5.61, P<0.01). Conclusions: Autologous transplantation of ADSCs into scar of rabbit at the early stage can inhibit the formation of hyperplastic scar, promote the quality of wound healing, and the mechanism may relate to the down-regulation of TGF-ß1, type Ⅰ collagen, and type Ⅲ collagen and the up-regulation of decorin induced by ADSCs.

Cytochalasin B inhibits the proliferation of human glioma U251 cells through cell cycle arrest and apoptosis.

Cytochalasin B (CB) is known to inhibit a number of cancer types, but its effects on gliomas are unknown. We examined the in vitro effects of CB on the proliferation of human glioma U251 cells, as well as determined its mechanism of action. Cell proliferation was determined using CCK-8. The effect of CB on U251 cell morphology was observed under a transmission electron microscope. Cell cycle distribution was assessed using propidium iodine and Giemsa staining, and cell apoptosis was determined by annexin V-fluorescein isothiocyanate/propidium iodide. Cell cycle-related proteins were determined by Western blot. CB effectively inhibited U251 cell proliferation in a dose- and time-dependent manner. The 24, 48, 72, and 96 h IC50 values were 6.41 x 10(-2), 9.76 x 10(-4), 2.57 x 10(-5), and 2.08 x 10(-5) M, respectively. CB increased the proportion of cells in the G2/M phase in a dose-dependent manner, thus increasing the mitotic index and decreasing cdc2 and cyclin B1 protein levels. CB induced morphological changes in the cytoskeleton. Additionally, 10(-5) M CB induced apoptosis in 23.4 ± 0.5% of U251 cells (P < 0.05 vs control group). Caspase-3, -8, and -9 activities were increased after CB treatment. CB inhibited U251 glioma cell proliferation by damaging the microfilament structure. CB also induced glioma cell apoptosis, suggesting that it may be an effective therapeutic agent against gliomas.

Enhanced susceptibility-weighted angiography (ESWAN) of cerebral arteries and veins at 1.5 Tesla.

OBJECTIVE: Enhanced susceptibility-weighted angiography (ESWAN) is a three-dimensional (3D) multi-echo gradient-echo sequence which consists of both magnitude and phase images. This study aims to demonstrate the feasibility of ESWAN for the depiction of both cerebral arteries and veins at 1.5 T by comparing with time-of-flight (TOF) MR angiography (MRA) and MR venography (MRV). METHODS: 13 healthy volunteers underwent both ESWAN and 3D-TOF-MRA examinations. Among them, nine volunteers underwent an additional two-dimensional-TOF-MRV examination. With regard to the ESWAN sequence, both maximum intensity projection (MIP) and minimum intensity projection (mIP) images were reconstructed and compared with MIP reconstructions of the TOF MRA and the TOF MRV. RESULTS: Concerning the depiction of the constituent segments of the Circle of Willis, as well as A1, A2, A3 (segments of the anterior cerebral artery), M1, M2 (segments of the middle cerebral artery), P1 and P2 (segments of the posterior cerebral artery), the value of the ESWAN MIP was comparable to that of the TOF MRA without regard to visualization of branches, vessel homogeneity and wall irregularities or slight stenosis. ESWAN-mIP visualized more deep cerebral veins than TOF MRV in this study. CONCLUSION: By use of either mIP reconstruction of a long echo data set or MIP reconstruction of a short echo data set, ESWAN allows simultaneous visualization of both cerebral veins and proximal segments of intracerebral arteries at 1.5 T. ADVANCES IN KNOWLEDGE: ESWAN acquires multiple images at different echo times corresponding to different T2* weightings, wherein a short echo TOF-MRA data set and a long echo susceptibility-weighted imaging-MRV data set are obtained simultaneously.

Impact of MTHFR polymorphisms on methylation of MGMT in glioma patients from Northeast China with different folate levels.

Hypomethylation of the O6-methylguanine-DNA-methyltransferase (MGMT) promoter in glioma cells has been associated with temozolomide resistance. S-adenosylmethionine (SAM), which is produced during folate metabolism, is the main source of methyl groups during DNA methylation. As a key enzyme during folate metabolism, polymorphisms of 5,10-methylenetetrahydrofolate reductase (MTHFR) may regulate folate end-products. We investigated the effect of typical polymorphisms of MTHFR (C677T and A1298C) on MGMT methylation based on different serum folate levels in patients with glioma from Northeast China. A total of 275 patients with glioma and 329 without malignant tumors were tested. Serum folate concentration was assayed by using the electrochemiluminescence immunoassay. MTHFR polymorphisms were detected by Taqman-Fluorescence quantitative polymerase chain reaction (PCR). Methylation-specific PCR was used to assess MGMT methylation. The constituent ratio of glioma patients below the serum folate biological reference value was significantly higher than that of the control population (P < 0.001). In patients with oligodendroglioma and glioblastoma, heterozygotes for the A1298C mutation were found in higher frequency than homozygotes or wild types (oligodendroglioma, P < 0.001; glioblastoma, P < 0.01). When grouped by the median or biological reference value of serum folate, only homozygotes for C677T with low levels of folate were significantly associated with decreased methylation of MGMT (median, P < 0.001; biological reference value, P = 0.036). These data suggest that, in combination with a negative folate balance in glioma patients, T/T genotypes in MTHFR C677T may be associated with MGMT demethylation.

Assessment of lateral geniculate nucleus atrophy with 3T MR imaging and correlation with clinical stage of glaucoma.

BACKGROUND AND PURPOSE: Although previous animal studies have shown structural changes in ocular hypertension such as atrophy of the LGN, such changes have not been thoroughly studied in human glaucoma patients nor correlation made with clinical stage. Our aim was to investigate prospectively LGN atrophy in patients with POAG using 3T MR imaging and correlation with the clinical stage of disease. MATERIALS AND METHODS: Twenty-six patients with known POAG and 26 age-matched healthy volunteers were included in this institutional review board-approved study. All subjects underwent imaging on a 3T MR imaging system with a PD and GM sequence. LGN height and volume were measured by 2 blinded neuroradiologists. Measurements were compared and correlated with clinical glaucoma severity as assessed by static threshold visual field parameters. RESULTS: Average maximum LGN height in patients with glaucoma on PD images was 4.36 ± 0.61 mm (right) and 4.31 ± 0.61 mm (left), significantly less (P < 10⁻³) than respective measurements of 5.05 ± 0.41 and 4.99 ± 0.41 mm in volunteers. With the GM sequences, such respective measurements were also less (P < 10⁻³) in patients with glaucoma (4.20 ± 0.71 mm right, 4.00 ± 0.85 mm left) versus respective measurements in volunteers (4.88 ± 0.51 mm right, 4.77 ± 0.47 mm left). Average LGN volumes in the patient group were 98.0 ± 27.2 mm³ (right) and 93.7 ± 25.8 mm³ (left) with the PD sequence versus respective measurements of 85.2 ± 27.1 and 80.5 ± 23.6 mm³ with the GM sequence. All height and volume measurements were greater in volunteers (P < 10⁻³). In the patient group, both maximum height and volume of the LGN with both sequences were significantly correlated with cumulative clinical glaucoma stage (P < .05). CONCLUSIONS: MR imaging measurements of LGN height and volume are diminished in patients with glaucoma, with the extent of atrophy correlating to clinical stage, suggesting a novel imaging marker of disease severity.

Human gastric adenocarcinoma allelotype on chromosomes 17 and 18.

Allelic losses of multiple chromosome loci in gastric adenocarcinoma suggest that inactivation of tumour suppressor genes in these regions may be important for tumourigenesis. To define deletion intervals and find candidate tumour suppressor genes involved in gastric adenocarcinoma pathogenesis, a genome-wide search for loss of heterozygosity (LOH) was conducted in 45 patients with primary gastric adenocarcinoma. Investigations using 29 microsatellite markers spanning chromosomes 17 and 18 showed allelic deletion in 29 (64%) specimens at one or more loci. Five LOH overlap regions, three newly identified as deletion regions, were defined: RI, D17S831 - D17S921 at 17p12-13.3; RII, D17S1868 - D17S787 at 17q21.3-22; RIII, D17S785 - D17S928 at 17q25.3; RIV, D18S61 - D18S1161 at 18q22; and RV, D18S462 - D18S70 at 18q22-q23. Eleven (24%) patients with chromosome 17 allelic loss also showed LOH on 18q, with at least one region of overlapping. LOH mapping showed allelic losses were widespread on both chromosomes and suggests the possibility that multiple tumour suppressor genes, including one or more that are unknown, might be inactivated in the aetiology of gastric adenocarcinoma.

A mathematical model of P53 gene regulatory networks under radiotherapy.

P53, a vital anticancer gene, controls the transcription and translation of a series of genes, and implement the cell cycle arrest and cell apoptosis by regulating their complicated signal pathways. Under radiotherapy, cell can trigger internal self-defense mechanisms in fighting against genome stresses induced by acute ion radiation (IR). To simulate the investigating of cellular responding acute IR at single cell level further, we propose a model of P53 gene regulatory networks under radiotherapy. Our model can successfully implement the kinetics of double strand breaks (DSBs) generating and their repair, ataxia telangiectasia mutated (ATM) activation, as well as P53-MDM2 feedback regulating. By comparing simulations under different IR dose, we can try to find the optimal strategy in controlling of IR dose and therapy time, and provide some theoretical analysis to obtain much better outcome of radiotherapy further.

A dynamic model for the p53 stress response networks under ion radiation.

P53 controls the cell cycle arrest and cell apoptosis through interaction with the downstream genes and their signal pathways. To stimulate the investigation into the complicated responses of p53 under the circumstance of ion radiation (IR) in the cellular level, a dynamic model for the p53 stress response networks is proposed. The model can be successfully used to simulate the dynamic processes of generating the double-strand breaks (DSBs) and their repairing, ataxia telangiectasia mutated (ATM) activation, as well as the oscillations occurring in the p53-MDM2 feedback loop.

[Catheter dilatation of arterial stenoses of supra-aortic vessels and late results]. / Katheterdilatation der arteriellen Stenosen supraaortaler Gefässe und Spätergebnisse.

Arterial stenoses of supra-aortic vessels, particularly of the subclavian and vertebral arteries, can be successfully treated by percutaneous transluminal angioplasty (PTA). In 125 patients primary success was achieved in 93% by PTA; 84 patients have been followed up for an average of 46 months and a clinical cure rate of 98.8% has been achieved. Apart from one re-stenosis all patients were symptom free and no other re-stenoses could be demonstrated. PTA of occlusions of supra-aortic vessels has less chances of success.