Profiled polyethylene terephthalate filaments that incorporate collagen and calcium phosphate enhance ligamentisation and bone formation

Polyethylene terephthalate (PET) artificial ligaments offer an unlimited source of ligaments without donor-site-related morbidity and with good mechanical properties for a rapid return to sporting activities. Developing PET artificial ligaments with excellent ligamentisation and ligament-bone healing is still a considerable challenge. This study aimed to investigate the effects of the profiled PET/collagen/calcium phosphate (PET/C/CaP) ligament upon cell growth, ligamentisation and ligament-bone healing in vitro and in vivo. Profiled PET/C/CaP filaments were made by melt-spinning process with 2 % CaP hybrid spinning and collagen coating. Rat mesenchymal stem cells (MSCs) were cultured on the profiled PET/C filaments for cytotoxicity, viability, scanning electron microscopy (SEM) and ligament-related gene expression analysis. MSCs' osteogenic capacity on the profiled PET/CaP filaments was identified by detecting osteogenic gene expression and alizarin red S staining. For in vivo verification, an animal study was performed to evaluate the effect of the profiled PET/C/CaP ligament in a rabbit knee medial collateral ligament reinforcement reconstruction model. The graft ligamentisation and bone formation were investigated by SEM, histology, microcomputed tomography and mechanical tests. The profiled PET/C filaments enhanced MSC proliferation and ligament-related gene expression. Furthermore, they enhanced osteogenic gene expression, alkaline phosphatase activity and mineralisation of MSCs. The in vivo study indicated that the profiled PET/C/CaP ligament enhanced ligamentous matrix remodelling and bone formation. Therefore, their use is an effective strategy for promoting MSCs' ligamentous and osteogenic potential in vitro and enhancing ligamentous matrix remodelling and bone formation in vivo.

Toll-like receptor signalling associated with immunomodulation of umbilical cord-derived mesenchymal stem cells in mice with systemic lupus erythematosus

With potent immunomodulatory activities, mesenchymal stem cells (MSCs) have the potential to be a beneficial treatment option for diseases with aberrant immune responses such as systemic lupus erythematosus (SLE). However, the underlying mechanisms remain largely unknown. Here, we used NZBWF1 mice as a SLE animal model to examine immunomodulation of MSCs as well as to assess the role of Toll-like receptor signalling in this circumstance. We found that mice receiving MSCs had a significant decrease in severity of proteinuria at 20 and 22 weeks of age (p = 0.009 and p = 0.022, respectively). Serum anti-dsDNA levels were significantly lower compared with the control group (p = 0.016 and p = 0.036, respectively). C3 and C4 levels were significantly higher at 22 weeks of age (p = 0.046 and p = 0.016, respectively). Altered expression of inflammation-associated cytokine profiles in the serum was also noted in mice receiving MSCs. Down-regulation of myeloid differentiation factor 88 (MyD88)-nuclear factor-κB (NF-κB) signalling in the liver was demonstrated by quantitative polymerase chain reaction, ELISA and Western blotting. In addition to demonstrating the beneficial effects of MSC treatment in NZBWF1 mice, our study provided the first evidence for the association of MyD88-NF-κB signalling and MSC-mediated immunomodulation in this disease.

Cloning and expression of the 1-aminocyclopropane-1-carboxylic oxidase gene from Agrostis stolonifera

A gene encoding 1-aminocyclopropane-1-carboxylic oxidase (ACO), which catalyzes the terminal step in ethylene biosynthesis, was isolated from Agrostis stolonifera. The AsACO gene is composed of 975 bp, encoding 324 amino acids. Three exons interspersed by two introns form AsACO gDNA. A BLAST search of the nucleotide sequence revealed a high level of similarity (79-91%) between AsACO and ACO genes of other plants. A phylogenetic tree was constructed via BLAST in the NCBI, and revealed the highest homology with wheat TaACO. The calculated molecular mass and predicted isoelectric point of AsACO were 36.25 and 4.89 kDa, respectively. Analysis of subcellular localization revealed that AsACO is located in the nucleus and cytoplasm. The Fe(II)-binding cofactors and cosubstrate were identified, pertaining to the ACO family. The expression patterns of AsACO were determined by quantitative real time PCR. AsACO expression was highest in the stem, and was strongly up-regulated in response to ethephon, methyl jasmonate, salicylic acid, and cold temperature, but down-regulated in response to drought and NaCl treatment. The protein encoded by AsACO exhibited ACC oxidase activity in vitro. Taken together, these findings suggest that AsACO contains domains common to the ACO family, and is induced in response to exogenous hormones. Conversely, some abiotic stress conditions can inhibit AsACO expression.

Concurrent hypopituitarism and leukemic retinopathy in a child with B-precursor acute lymphoblastic leukemia and isolated central nervous system relapse

Hypopituitarism in leukemia is very rare. In addition, central nervous system (cns) relapse and leukemic retinopathy in childhood acute lymphoblastic leukemia (all) have declined with the use of modern systemic chemotherapy that includes cns prophylaxis. Here, we report the case of a 4-year-old girl who received chemotherapy and intrathecal therapy without cns radiation after a diagnosis of B-precursor all without cns involvement. Three months after chemotherapy completion, she presented with lower-extremity weakness and was diagnosed with an isolated cns relapse. Concurrent hypopituitarism and leukemic retinopathy were also found. After receiving craniospinal radiotherapy and systemic chemotherapy, her retinopathy and vision improved. She is now in complete remission, and she is still on chemotherapy according to the guideline from the Pediatric Oncology Group. Although rare, hypopituitarism and leukemic retinopathy should be taken into consideration in patients with cns involvement by leukemia.

Expression of an alfalfa (Medicago sativa L.) peroxidase gene in transgenic Arabidopsis thaliana enhances resistance to NaCl and H2O2

Peroxidases (PODs) are enzymes that play important roles in catalyzing the reduction of H2O2 and the oxidation of various substrates. They function in many different and important biological processes, such as defense mechanisms, immune responses, and pathogeny. The POD genes have been cloned and identified in many plants, but their function in alfalfa (Medicago sativa L.) is not known, to date. Based on the POD gene sequence (GenBank accession No. L36157.1), we cloned the POD gene in alfalfa, which was named MsPOD. MsPOD expression increased with increasing H2O2. The gene was expressed in all of the tissues, including the roots, stems, leaves, and flowers, particularly in stems and leaves under light/dark conditions. A subcellular analysis showed that MsPOD was localized outside the cells. Transgenic Arabidopsis with MsPOD exhibited increased resistance to H2O2 and NaCl. Moreover, POD activity in the transgenic plants was significantly higher than that in wild-type Arabidopsis. These results show that MsPOD plays an important role in resistance to H2O2 and NaCl.

Molecular cloning and characterization of a chlorophyll degradation regulatory gene (ZjSGR) from Zoysia japonica

The stay-green gene (SGR) is a key regulatory factor for chlorophyll degradation and senescence. However, to date, little is known about SGR in Zoysia japonica. In this study, ZjSGR was cloned, using rapid amplification of cDNA ends-polymerase chain reaction (PCR). The target sequence is 831 bp in length, corresponding to 276 amino acids. Protein BLAST results showed that ZjSGR belongs to the stay-green superfamily. A phylogenetic analysis implied that ZjSGR is most closely related to ZmSGR1. The subcellular localization of ZjSGR was investigated, using an Agrobacterium-mediated transient expression assay in Nicotiana benthamiana. Our results demonstrated that ZjSGR protein is localized in the chloroplasts. Quantitative real time PCR was carried out to investigate the expression characteristics of ZjSGR. The expression level of ZjSGR was found to be highest in leaves, and could be strongly induced by natural senescence, darkness, abscisic acid (ABA), and methyl jasmonate treatment. Moreover, an in vivo function analysis indicated that transient overexpression of ZjSGR could accelerate chlorophyll degradation, up-regulate the expression of SAG113, and activate ABA biosynthesis. Taken together, these results provide evidence that ZjSGR could play an important regulatory role in leaf chlorophyll degradation and senescence in plants at the molecular level.

Dasatinib for a child with Philadelphia chromosome-positive acute lymphoblastic leukemia and persistently elevated minimal residual disease during imatinib therapy

Imatinib has improved outcomes in patients with Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (all). Minimal residual disease (mrd) is a useful tool for predicting leukemia relapse. However, there is no consensus on how to treat children with elevation of BCR-ABL transcripts but no evidence of hematologic relapse during chemotherapy combined with imatinib. Here, we report the case of a child with Ph+ all who had persistent elevation of mrd, but no evidence of hematologic relapse while receiving imatinib plus intensive chemotherapy. Dasatinib was substituted for imatinib because no suitable donor for allogeneic hematopoietic stem-cell transplantation (hsct) was available. Less-intensive chemotherapy with methotrexate and 6-mercaptopurine was administered concomitantly. No serious adverse events were encountered. With continuous dasatinib combined with chemotherapy, but no allogeneic hsct, our patient reached complete molecular remission and has been in complete molecular remission for more than 13 months. This report is the first about the long-term use of dasatinib in patients with Ph+ all and mrd elevation but hematologic remission during imatinib chemotherapy. In a similar situation, chemotherapy combined with dasatinib instead of allogeneic hsct could be considered to avoid hsct-related mortality and morbidity. Clinical trials are needed.

Designing optical-fiber modulators by using magnetic fluids

To reduce interface loss between optical fibers and devices in telecommunication systems, the development of an optical-fiber-based device that can be fused directly with fibers is important. A novel optical modulator consisting of a bare fiber core surrounded by magnetic fluids instead of by a SiO2 cladding layer is proposed. Applying a magnetic field raises the refractive index of the magnetic fluid. Thus we can control the occurrence of total reflection at the interface between the fiber core and the magnetic fluid when light propagates along the fiber. As a result, the intensity of the outgoing light is modulated by variation in field strength. Details of the design, fabrication, and working properties of such a modulator are presented.

Synthesis and cytotoxicity of methyl-4,8-dihydrobenzo[1,2-b:5,4-b']dithiophene-4,8-dione derivatives

2- and 3-Methyl-4,8-dihydrobenzo[1,2-b:5,4-b']dithiophene-4,8-dione and related derivatives were synthesized and evaluated in vitro by NCI against eight cancer types. Compounds 12-15 showed significant activity against melanoma, NCI-H23 non-small cell lung cancer, and MDA-MB-435 and MDA-N breast cancer cell lines; 2-hydroxymethyl-4,8-dihydrobenzo[1,2-b:5,4-b']dithiophene-4,8-dion e (13) showed the highest activity against melanoma (mean log GI50 = -7.74) and the highest overall potency (mean log GI50 = -6.99).

Synthesis and cytotoxicity of 2-acetyl-4,8-dihydrobenzodithiophene-4, 8-dione derivatives

2-Acetyl-4,8-dihydrobenzo[1,2-b:4,5-b']dithiophene-4,8-dione (9) and 2-acetyl-4,8-dihydrobenzo[1,2-b:5,4-b']dithiophene-4,8-dione (19), together with 10 related mono- and disubstituted derivatives, were synthesized and evaluated in vitro by NCI against eight cancer types. All compounds showed significant activity against melanoma, HL-60 leukemia, NCI-H23 non-small-cell lung cancer, OVCAR-3 ovarian cancer, and MDA-MB-435 and MDA-N breast cancer cell lines. Compound 11, 2-(1'-acetoxyethyl)-4,8-dihydrobenzo[1,2-b:4,5-b']dithiophene-4, 8-dione, showed the highest overall potency (mean GI50 = 40 nM).

Synthesis and cytotoxicity of acetyl-4H,9H-naphtho[2,3-b]thiophene-4,9-diones

Several new acetyl-4H,9H-naphtho[2,3-b]thiophene-4,9-diones were synthesized and evaluated for in vitro cytotoxicity by NCI against seven cancer cell types. 2,7-Diacetyl naphtho[2,3-b]thiophene-4,9-dione (9) showed significant cytotoxicity against leukemia cells with log GI50 values of -7.61 against SR cells and -7.18 against MOLT-4 cells. 3-Acetyl-naphtho[2,3-b]thiophene-4,9-dione (6) also demonstrated potent cytotoxicity in the latter cell line with log GI50 < -8.

RNase E cleaves at multiple sites in bubble regions of RNA I stem loops yielding products that dissociate differentially from the enzyme

Earlier work has shown that RNase E cleaves RNAI, the antisense repressor of replication of ColE1-type plasmids, producing pRNAI-5, whose further decay is mediated by the poly(A)-dependent activity of polynucleotide phosphorylase and other 3' to 5' exonucleases. Using a poly(A) polymerase-deficient strain to impede exonucleolytic decay, we show that RNAI is additionally cleaved by RNase E at multiple sites, generating a series of decay intermediates that are differentially retained by the RNA binding domain (RBD) of RNase E. Primer extension analysis of RNAI decay intermediates and RNase T1 mapping of the cleavage products of RNAI generated in vitro by affinity-purified RNase E showed that RNase E can cleave internucleotide bonds in the bubble regions of duplex RNA segments and in single-stranded regions. Chemical in situ probing of a complex formed between RNAI and the RBD indicates that binding to the RBD destabilizes RNAI secondary structure. Our results suggest a model in which a series of sequential RNase E-mediated cleavages occurring at multiple sites of RNAI, some of which may be made more accessible to RNase E by the destabilizing effects of its RBD, generate RNA fragments that are further degraded by poly(A)-dependent 3' to 5' exonucleases.

Cochlear fistula in chronic otitis media with cholesteatoma

Labyrinthine fistula in chronic otitis media with cholesteatoma most commonly involves the horizontal semicircular canal. We report three cases of cochlear fistula in chronic otitis media with cholesteatoma. All of them had a long history of otorrhea. One patient had total hearing loss of the affected side. The other two patients had conductive hearing loss. Radical mastoidectomy had been done in all cases. Cholesteatoma in the tympanic cavity destroyed the basal turn of the cochlea. These fistulas were sealed with muscle or Gelfoam with streptomycin. We found no fistula in the semicircular canal in any of the three cases. We report three cases of cochlear fistula in chronic otitis media with cholesteatoma, and review the literature.

[On the method of hyperthermic chemotherapy by regional isolated perfusion for tumors of lower extremities]

From August 1990 to June 1993, 30 patients with osteosarcoma of lower extremities were treated with chemotherapy by hyperthermic regional isolated perfusion. There were 19 male and 11 female with a mean age of 21 (15-28) years. All of the tumors were located in the lower limbs: 20 on the femora, 9 on the tibiae and 1 on the fibula. Chemotherapy was going on for 60 minutes during hyperthermic regional isolated perfusion. Temperature was kept at 42 degrees C in deep soft tissue around the tumor during perfusion. The results showed that local edema of the limbs were reduced observably, tumors were shrunken and hardened after perfusion. Perimeter of the limbs were decreased and mobility of the limbs increased. Pathological examination indicated that all of the tumors responded well to the chemotherapy by perfusion and 90%-95% of the osteosarcoma cells were destroyed. Two cases were complicated with compression syndrome, and 1 with renal failure. The authors would suggest that hyperthermic regional isolated perfusion is an effective chemotherapeutic method in management of malignant tumors of limbs.