Guided bone regeneration using acellular bovine pericardium in a rabbit mandibular model: in-vitro and in-vivo studies

BACKGROUND AND OBJECTIVE

To investigate the feasibility of acellular bovine pericardium (BP) for guided bone regeneration (GBR) in vitro and in vivo. The success of GBR relies on the fact that various cellular components possess different migration rates into the defect site and that a barrier membrane plays a significant role in these processes.

MATERIAL AND METHODS

BP membrane was isolated and decellularized using an enzymatic method. The microarchitecture, mechanical properties, cytotoxicity and cell chemotaxis properties of the acellular BP were evaluated in vitro, and the in-vivo efficacy of the acellular BP was also investigated in a rabbit mandibular model.

RESULTS

The acellular BP membrane possessed an interconnected fibrous structure. Glutaraldehyde (GA) treatment was efficient for enhancement of the mechanical properties of the acellular BP bur and resulted in negligible cytotoxicity. After 16 wk, standardized osseous defects created in the rabbit mandible, and covered with acellular BP, were associated with an enhanced deposition of mineralized tissue when compared with defects left to spontaneous healing.

CONCLUSION

GA-treated acellular BP is promising as a barrier membrane for GBR for further in-vivo and clinical studies.

The features of breast lymphoma on MRI

OBJECTIVE

To investigate the morphological features of breast lymphoma (BL) on MRI.

METHODS

MRI features of 20 patients with BL (12 primary and 8 secondary) were reviewed according to Breast Imaging-Reporting and Data System categories.

RESULTS

19 cases were unilateral and 1 was bilateral. According to the enhanced images, of the 20 cases, BL presented as a mass in 11 (55%), as an enhancement with no mass effect in 7 (35%) and as a mass and mixed enhancement with no mass effect in 2 (10%). There were 38 masses and 44 lesions with no mass effect in our study. All lesions showed mild heterogeneous internal enhancement. For lesions with mass effect, the margins were smooth in 32% (12/38) and irregular in 68% (26/38); and the shape was oval in 87% (32/38). Kinetic curve assessment (13 cases, 38 lesions) revealed that the average initial rise rate was 104%. The type II enhancement curve appeared in 55% (21/38) of lesions. No significant differences between the primary and secondary BL were observed for any of the MRI features.

CONCLUSION

BL mostly appeared oval with irregular margins showing mild heterogeneous internal enhancement and/or as enhanced lesions with no mass effect with mild heterogeneous internal enhancement.

ADVANCES IN KNOWLEDGE

Some special features on MRI are useful for the diagnosis of BL.

Overexpression of stearoyl-CoA desaturase 1 in bone-marrow mesenchymal stem cells increases osteogenesis

AIM

The goal of this study was to examine the relationship between stearoyl-CoA desaturase 1 (SCD1) and osteogenesis in bone marrow mesenchymal stem cells (BM-MSCs).

METHODS

SCD1 was overexpressed in BM-MSCs using lentiviral transduction. Then, osteogenesis was induced by low glucose DMEM (10% fetal bovine serum). Alkaline phosphatase (ALP) activity assays, Western blot analyses of SCD1 and osteocalcin, and stainings for ALP and alizarin red were done to assess the extent of osteogenesis in BM-MSCs.

RESULTS

ALP activity was markedly higher in the SCD1 overexpressing cells compared with cells transduced with empty vector or control (untransduced) cells at 1 and 2 weeks after osteogenic induction. By contrast, ALP activities were comparable between control cells and cells transduced with empty vector. Western blot analysis demonstrated that osteocalcin levels were higher in the SCD1 overexpressing cells, compared with cells transduced with empty vector or control cells, at 1 and 2 weeks after osteogenic induction. These findings were corroborated by stainings for ALP and alizarin red that demonstrated a more active osteogenesis in the SCD1 overexpressing cells 2 weeks after osteogenic induction.

CONCLUSION

Increased levels of SCD1 enhance osteogenesis in BM-MSCs.

SOX4 is associated with poor prognosis in prostate cancer and promotes epithelial-mesenchymal transition in vitro

BACKGROUND

The SOX4 transcription factor is involved in the development and cell fate decision. Although upregulation of SOX4 has been described in human prostate cancer (PCa), the prognostic value of SOX4 and its exact role in PCa progression remain unclear.

METHODS

Three tissue microarrays were constructed from 241 Chinese PCa patients who underwent TURP. Immunohistochemistry (IHC) was used to detect the expression of SOX4. Genetic aberrations of epidermal growth factor receptor and HER2 were detected by fluorescence in situ hybridization. The effect of SOX4 on proliferation was evaluated by MTT (methyl thiazolyl tetrazelium), and cell migration and invasion were evaluated by transwell and wound-healing assays. The distribution of cell-cycle phase was analyzed by flow cytometry. Real-time PCR and western blot were used to study transcript and protein levels.

RESULTS

Using tissue microarray, we found that SOX4 was overexpressed in 33.0% (76/230) Chinese PCa patients by IHC. SOX4 overexpression was significantly associated with high Gleason scores (P=0.009) and the presence of distant metastasis (P=0.023). Additionally, SOX4 overexpression was significantly correlated with high Ki67 labeling index (P=0.005) and tended to associate with amplification of HER2 (P=0.052) in our cohort. Notably, SOX4 was correlated with cancer-specific mortality of PCa patients by Kaplan-Meier analysis (P=0.001). Multivariate Cox regression analysis indicated that SOX4 was an unfavorable independent prognostic factor in Chinese PCas (P=0.017). SOX4 overexpression enhanced proliferation of Vcap cells and siRNA knockdown of SOX4 significantly decreased Vcap cell migration and invasion, suggesting a role of SOX4 in cancer metastasis. Additionally, flow cytometry DNA analysis revealed that siRNA SOX4 leads to significant accumulation of cells in the S phase and marked decrease of cells in the G2/M phase. Further in vitro study revealed that SOX4 silencing could inhibit TGF-β (transforming growth factor-β)-induced epithelial-mesenchymal transition (EMT) in Vcap cells. Overexpression of SOX4 could promote the EMT phenotype in Vcap cells.

CONCLUSIONS

Our results define an important role for SOX4 in the progression of PCa by orchestrating EMT and may serve as a prognostic marker for PCa patients.

An animal model of Kashin-Beck disease induced by a low-nutrition diet and exposure to T-2 toxin

OBJECTIVE

We investigated the combined roles of a low-nutrition diet (low levels of protein, iodine, and selenium) and T-2 toxin in bone development and to establish an experimental animal model of Kashin-Beck disease (KBD) that reliably mimics the disease's pathological changes for further study of the pathogenesis and prevention of the disease.

METHODS

Sprague-Dawley rats were randomly divided among four groups: group A, normal diet; group B, normal diet plus T-2 toxin; group C, low-nutrition diet; and group D, low-nutrition diet plus T-2 toxin exposure. The radiographic and histopathological changes in the tibial growth zone, plate cartilage and metaphysis were examined.

RESULTS

In group D, all epiphyseal plates were blurred, thin, and irregular. Tibias were significantly shorter in group D than in groups A and B. After 4 weeks, epiphyseal plates showed chondrocyte necrosis, with the more obvious necrosis appearing in groups C and D. The positive rate of lamellar necrosis was significantly higher in group D than in groups B and A (P < 0.01). In group D, metaphyseal trabecular bone was sparse, disordered, and disrupted, and massive transverse trabecular bone appeared in the metaphysis at 12 weeks.

CONCLUSIONS

A rat model of KBD induced by a low-nutrition diet and T-2 toxin exposure demonstrated radiographic and histopathological abnormalities of the proximal epiphyseal plate and the tibial metaphysis that are very similar to the bone changes found in patients with KBD. This animal model will be helpful for further study of the pathogenesis and prevention of KBD.

First Report of a Chaetomella sp. Causing a Leaf Spot on Sansevieria trifasciata in China

Sansevieria trifasciata originates from tropical West Africa. It is widely planted as a potted ornamental in China for improving indoor air quality (1). In February 2011, leaves of S. trifasciata plants in an ornamental market of Anle, Luoyang City, China, were observed with sunken brown lesions up to 20 mm in diameter, and with black pycnidia present in the lesions. One hundred potted plants were examined, with disease incidence at 20%. The symptomatic leaves affected the ornamental value of the plants. A section of leaf tissue from the periphery of two lesions from a plant was cut into 1 cm² pieces, soaked in 70% ethanol for 30 s, sterilized with 0.1% HgCl₂ for 2 min, then washed five times in sterilized distilled water. The pieces were incubated at 28°C on potato dextrose agar (PDA). Colonies of two isolates were brown with submerged hyphae, and aerial mycelium was rare. Abundant and scattered pycnidia were reniform, dark brown, and 200 to 350 × 100 to 250 μm. There were two types of setae on the pycnidia: 1) dark brown setae with inward curved tops, and 2) straight, brown setae. Conidia were hyaline, unicellular, cylindrical, and 3.75 to 6.25 × 1.25 to 2.50 μm. Morphological characteristics suggested the two fungal isolates were a Chaetomella sp. To confirm pathogenicity, six mature leaves of a potted S. trifasciata plant were wounded with a sterile pin after wiping each leaf surface with 70% ethanol and washing each leaf with sterilized distilled water three times. A 0.5 cm mycelial disk cut from the margin of a 5-day-old colony on a PDA plate was placed on each pin-wounded leaf, ensuring that the mycelium was in contact with the wound. Non-colonized PDA discs were placed on pin-wounded leaves as the control treatment. Each of two fungal isolates was inoculated on two leaves, and the control treatment was done similarly on two leaves. The inoculated plant was placed in a growth chamber at 28°C with 80% relative humidity. After 7 days, inoculated leaves produced brown lesions with black pycnidia, but no symptoms developed on the control leaves. A Chaetomella sp. was reisolated from the lesions of inoculated leaves, but not from the control leaves. An additional two potted plants were inoculated using the same methods as replications of the experiment, with identical results. To confirm the fungal identification, the internal transcribed spacer (ITS) region of rDNA of the two isolates was amplified using primers ITS1 and ITS4 (2) and sequenced. The sequences were identical (GenBank Accession No. KC515097) and exhibited 99% nucleotide identity to the ITS sequence of an isolate of Chaetomella sp. in GenBank (AJ301961). To our knowledge, this is the first report of a leaf spot of S. trifasciata caused by Chaetomella sp. in China as well as anywhere in the world. References: (1) X. Z. Guo et al. Subtropical Crops Commun. Zhejiang 27:9, 2005. (2) T. J. White et al. PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, San Diego, CA, 1990.

Exposure to bisphenol A disrupts meiotic progression during spermatogenesis in adult rats through estrogen-like activity

The effect of bisphenol A (BPA) on the reproductive system is highly debated but has been associated with meiotic abnormalities. However, evidence is lacking with regard to the mechanisms involved. In order to explore the underlying mechanisms of BPA-induced meiotic abnormalities in adult male rats, we exposed 9-week-old male Wistar rats to BPA by gavage at 0, 2, 20 or 200 μg/kg body weight (bw)/day for 60 consecutive days. 17β-Estradiol (E2) was administered at 10 μg/kg bw/day as the estrogenic positive control. Treatments with 200 μg/kg bw/day of BPA and E2 significantly decreased sperm counts and inhibited spermiation, characterized by an increase in stage VII and decrease in stage VIII in the seminiferous epithelium. This was concomitant with a disruption in the progression of meiosis I and the persistence of meiotic DNA strand breaks in pachytene spermatocytes,and the ataxia-telangiectasia-mutated and checkpoint kinase 2 signal pathway was also activated; Eventually, germ cell apoptosis was triggered as evaluated by terminal dUTP nick-end labeling assay and western blot for caspase 3. Using the estrogen receptor (ER) antagonist ICI 182780, we determined that ER signaling mediated BPA-induced meiotic disruption and reproductive impairment. Our results suggest that ER signaling-mediated meiotic disruption may be a major contributor to the molecular events leading to BPA-related male reproductive disorders. These rodent data support the growing association between BPA exposure and the rapid increase in the incidence of male reproductive disorders.

Treatment modality selection and prognosis of early stage small cell lung cancer: retrospective analysis from a single cancer institute

We evaluated the role of surgery followed by either chemotherapy (ChT) alone or chemotherapy and thoracic radiotherapy (ChT/TRT) versus sequential ChT/TRT in patients with clinical stage I or stage II small cell lung cancer (SCLC). Ninety-six patients received surgery (complete resection) followed by either ChT alone or ChT/TRT (Group I), while 49 patients were treated exclusively with sequential ChT/TRT (Group II). The ChT regimens consisted of either carboplatin/etoposide or cisplatin/etoposide. The total TRT dose was 50-60 Gy. For the whole group (n = 145), the median survival time was 54 months, and the 5-year overall survival (OS) rate was 48%. The corresponding figures for Group I were 91 months and 57%, respectively, and for Group II, they were 34.6 months and 31.4% respectively (P = 0.004). Multivariate analysis revealed that a Karnofsky Performance Status score ≥ 80 [hazard ratio (HR), 0.281; P = 0.015] and the treatment modality including surgery (HR, 0.503; P = 0.004) were independent favourable prognostic factors for OS.

Naphthalene-ring Containing Thermotropic Copolyester and its Blends with PET

A series of thermotropic liquid crystalline copolyesters based on p-acetoxybenzoic acid, 2,7-diacetoxynaphthalene, terephthalic acid and polyethylene 2,6-naphthalate were prepared via melt transesterification. Their thermotropic liquid crystalline behavior was studied by visual observation on the hot stage of a polarized light microscope. The dependence of the crystallizability and melting temperature of the copolyesters on the 2,7-diace-toxynaphthalene content was examined by x-ray diffraction and differential scanning calorimetry. A blend sample was prepared by physically mixing 40% thermotropic copolyester and 60% polyethylene terephthalate and the phase-separated charackter of the copolyester and PET in the blend was proved by TOT and dynamic mechanical measurements. The SEM micrographs of the as-spun fibers of the blend show separation of the two phases. The highly oriented macromolecules and the fibril alignment of the mesomorphic copolyester in the blend has also been revealed after the dissolution of the PET phase in a solvent.

Prevalence of cardiovascular disease and risk factors in the Chinese population with impaired glucose regulation: the 2007-2008 China national diabetes and metabolic disorders study

Cardiovascular disease (CVD) is one of the most common chronic diseases in China. This aim of this study is to determine the prevalence of CVDs and risk factors in Chinese impaired glucose regulation subjects.We used a multistage, stratified sampling method to select subjects from the general Chinese population aged 20 years and older. Subjects underwent an oral glucose tolerance test to identify normal glucose tolerance (NGT) and impaired glucose regulation including isolated impaired fasting glucose (i-IFG), impaired glucose tolerance (i-IGT), and combined IFG/IGT and diabetic mellitus (DM). A logistic regression analysis was performed to examine the association between glucose abnormalities and CVD events.We identified that 34 293 subjects had NGT, 1 469 i-IFG, 4 571 i-IGT, 957 IFG/IGT and 4 949 DM. The age-sex standardized prevalence rate of cardiovascular disease was 1.06% (95% CI 0.87-1.28), 1.79% (95% CI 1.37-2.33) and 3.83% (95% CI 2.79-5.24) in NGT, impaired glucose regulation and DM, respectively. Among impaired glucose subjects, prevalence of defined CVD risk factors (smoking, overweight, obesity, hypertension and dyslipidemia) was 29.52% (95% CI: 27.8-31.21), 36.25% (95% CI: 34.29-38.26), 10.05% (95% CI: 8.86-11.37), 36.43% (95% CI: 34.53-38.36) and 69.96% (95% CI: 67.87-71.98), respectively. Compared to 1 risk factor, the odds ratios (ORs) of CVDs with 2, 3 or 4 risk factors were 1.94 (95% CI: 0.74-5.09), 2.76 (95% CI: 1.06-7.21) and 5.84 (95% CI: 1.68-20.26), respectively. Additionally, compared to i-IFGs, ORs of CVDs with i-IGT and IFG/IGT were 2.88 (95%CI 1.36-6.01) and 2.12 (95% CI 0.83-5.44), respectively.The prevalence of cardiovascular risk factors was high in the Chinese impaired glucose regulation population. The postprandial hyperglycemia is more associated with CVD than isolated fasting hyperglycemia.

Clinicopathologic characteristics of YES-associated protein 1 overexpression and its relationship to tumor biomarkers in gastric cancer

Yes-associated protein 1 (YAP1), a downstream effector of the Hippo pathway, plays an important role in the development and progression of multiple malignancies, including human gastric cancer (GC). However, the clinical significance of YAP1 expression in GC needs to be comprehensively explored. Based on the pivotal role of YAP1 in the hippo pathway, we explored the clinicopathologic characteristics of YAP1 overexpression and its relationship to some tumor biomarkers in GC. Ninety cases of GC, chronic gastritis (CG) and CG with dysplasia samples were collected, and clinical data of all patients with GC were analyzed. The expression of YAP1 was assessed using immunohistochemical assay in biopsy samples. As a result, almost all the GC samples, but few CG and dysplasia samples showed YAP1 positive staining mainly in the nucleus. The expression of YAP1 was found in GC tissues with higher strong reactivity rate, compared with dysplasia and CG tissues (79.2 percent vs 47.1 percent and 15 percent, each P&#60;0.001), and its expression level was elevated with the ascending order of GC malignancy. However, no significant correlation was found between the expression of YAP1 and epidermal growth factor receptor (EGFR) with gender, age, gross stage, degree of differentiation, tumor size, TNM staging, perineural infiltration, vascular invasion, lymphatic vessel invasion and lymph node metastases in patients with GC (each P&#62;0.05). Furthermore, Spearman rank correlation analysis also showed no correlation of YAP1 with EGFR, Ki-67, CD34 and topoisomerase II (TOP II). Taken together, YAP1 is highly expressed in GC tissues compared with the dysplasia and CG tissues and its expression level is elevated with the ascending order of tumor malignancy; but, YAP1 expression does not correlate with the clinicopathologic characteristics and the expression of EGFR, Ki-67, CD34 and TOP II in GC.

The proprotein convertase furin is required for trophoblast syncytialization

The multinucleated syncytial trophoblast, which forms the outermost layer of the placenta and serves multiple functions, is differentiated from and maintained by cytotrophoblast cell fusion. Deficiencies in syncytial trophoblast differentiation or maintenance likely contribute to intrauterine growth restriction and pre-eclampsia, two common gestational diseases. The cellular and molecular mechanisms governing trophoblast syncytialization are poorly understood. We report here that the proprotein convertase furin is highly expressed in syncytial trophoblast in the first trimester human placentas, and expression of furin in the syncytiotrophoblast is significantly lower in the placentas from pre-eclamptic patients as compared with their gestational age-matched control placentas. Using multiple experimental models including induced fusion of choriocarcinoma BeWo cells and spontaneous fusion of primary cultured cytotrophoblast cells or placental explants, we demonstrate that cytotrophoblast cell fusion and syncytialization are accompanied by furin expression. Furin-specific siRNAs or inhibitors inhibit cell fusion in BeWo cells, as well as trophoblast syncytialization in human placental explants. Furthermore, type 1 IGF receptor (IGF1R) is indicated in this study as a substrate of furin, and processing of IGF1R by furin is an essential mechanism for syncytialization. Finally, using lentivirus-mediated RNAi targeting to mouse trophectoderm, we demonstrate that furin function is required for the development of syncytiotrophoblast structure in the labyrinth layer, as well as for normal embryonic development.

High-resolution MRI of the intraparotid facial nerve based on a microsurface coil and a 3D reversed fast imaging with steady-state precession DWI sequence at 3T

BACKGROUND AND PURPOSE

3D high-resolution MR imaging can provide reliable information for defining the exact relationships between the intraparotid facial nerve and adjacent structures. The purpose of this study was to explore the clinical value of using a surface coil combined with a 3D-PSIF-DWI sequence in intraparotid facial nerve imaging.

MATERIALS AND METHODS

Twenty-one healthy volunteers underwent intraparotid facial nerve scanning at 3T by using the 3D-PSIF-DWI sequence with both the surface coil and the head coil. Source images were processed with MIP and MPR to better delineate the intraparotid facial nerve and its branches. In addition, the SIR of the facial nerve and parotid gland was calculated. The number of facial nerve branches displayed by these 2 methods was calculated and compared.

RESULTS

The display rates of the main trunk, divisions (cervicofacial, temporofacial), and secondary branches of the intraparotid facial nerve were 100%, 97.6%, and 51.4% by head coil and 100%, 100%, and 83.8% by surface coil, respectively. The display rate of secondary branches of the intraparotid facial nerve by these 2 methods was significantly different (P < .05). The SIRs of the intraparotid facial nerve/parotid gland in these 2 methods were significantly different (P < .05) at 1.37 ± 1.06 and 1.89 ± 0.87, respectively.

CONCLUSIONS

The 3D-PSIF-DWI sequence combined with a surface coil can better delineate the intraparotid facial nerve and its divisions than when it is combined with a head coil, providing better image contrast and resolution. The proposed protocol offers a potentially useful noninvasive imaging sequence for intraparotid facial nerve imaging at 3T.

Mechanochemical Milling of PP/Ground Tire Rubber Blends in Solid-State

In this study, solid-state mechanochemical milling was investigated as a viable strategy to produce high performance blends composed of polypropylene (PP) and ground tire rubber (GTR), thereby providing a potentially new route to recycle discarded tires. The improved dispersion of the blends after mechanochemical milling was confirmed by fluorescence microscopy and polarized optical microscopy (POM) observation. After 20 cycles of milling, the tensile strength of PP/GTR (100/40) blends was enhanced by 13.8%, and the elongation at break was over 12 times than that of the unpretreated blend. The formation of smaller and less ordered spherulites of PP after mechanochemical milling as confirmed by POM observation and wide-angle X-ray diffraction analysis might be the reason for the significant enhancement of the elongation at break.

Hyperthermia enhances mapatumumab-induced apoptotic death through ubiquitin-mediated degradation of cellular FLIP(long) in human colon cancer cells

Colorectal cancer is the third leading cause of cancer-related mortality in the world; the main cause of death of colorectal cancer is hepatic metastases, which can be treated with hyperthermia using isolated hepatic perfusion (IHP). In this study, we report that mild hyperthermia potently reduced cellular FLIP(long), (c-FLIP(L)), a major regulator of the death receptor (DR) pathway of apoptosis, thereby enhancing humanized anti-DR4 antibody mapatumumab (Mapa)-mediated mitochondria-independent apoptosis. We observed that overexpression of c-FLIP(L) in CX-1 cells abrogated the synergistic effect of Mapa and hyperthermia, whereas silencing of c-FLIP in CX-1 cells enhanced Mapa-induced apoptosis. Hyperthermia altered c-FLIP(L) protein stability without concomitant reductions in FLIP mRNA. Ubiquitination of c-FLIP(L) was increased by hyperthermia, and proteasome inhibitor MG132 prevented heat-induced downregulation of c-FLIP(L). These results suggest the involvement of the ubiquitin-proteasome system in this process. We also found lysine residue 195 (K195) to be essential for c-FLIP(L) ubiquitination and proteolysis, as mutant c-FLIP(L) lysine 195 arginine (arginine replacing lysine) was left virtually un-ubiquitinated and was refractory to hyperthermia-triggered degradation, and thus partially blocked the synergistic effect of Mapa and hyperthermia. Our observations reveal that hyperthermia transiently reduced c-FLIP(L) by proteolysis linked to K195 ubiquitination, which contributed to the synergistic effect between Mapa and hyperthermia. This study supports the application of hyperthermia combined with other regimens to treat colorectal hepatic metastases.