The purpose of this study was to compare postoperative range of motion and functional outcomes among patients who received high-flexion total knee arthroplasty using cruciate-retaining (CR-Flex) and posterior-stabilized (PS-Flex) type prostheses.
Materials and Methods
Among 127 patients (186 knees) who underwent high-flexion total knee arthroplasty between 2005 and 2007, 92 knees were placed in the CR-Flex group, and 94 knees were placed in the PS-Flex group. After two years of postoperative follow-up, clinical and radiographic data were reviewed. Postoperative non-weight-bearing range of knee motion, angle of flexion contracture and functional outcomes based on the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) functional sub-scale were assessed and compared between the two groups.
After the 2-year postoperative period, the mean range of motion was 131° in the CR-Flex group and 133° in the PS-Flex group. There were no significant differences in postoperative range of motion between the two groups. Only age at operation and preoperative range of motion were significantly associated with postoperative range of motion after high-flexion total knee arthroplasty. Postoperative functional outcomes based on the WOMAC functional sub-scale were slightly better in the CR-Flex group (9.2±9.1 points) than in the PS-Flex group (11.9±9.6 points); however, this difference was not statistically significant (p=non-significant).
The retention or substitution of the posterior cruciate ligament does not affect postoperative range of motion (ROM) or functional outcomes, according to 2 years of postoperative follow-up of high-flexion total knee arthroplasty.
Total knee arthroplasty; range of motion; functional outcomes; cruciate-retaining; posterior-stabilized; high-flexion
We evaluated the results of more than 10 years of follow-up of total hip arthroplasty using a second-generation cementless femoral prosthesis with a collar and straight distal fixation channels.
Materials and Methods
One hundred five patients (129 hips) who underwent surgery between 1991 and 1996 for primary total hip arthroplasty using cementless straight distal fluted femoral stems were followed for more than 10 years. Ninety-four hips in 80 patients were available for clinical and radiologic analysis. The mean age at the time of surgery was 47 years, and the mean duration of follow-up was 14.3 years.
The mean Harris hip scores had improved from 58 points to 88 points at the time of the 10-year follow-up. Activity-related thigh pain was reported in nine hips (10%). At the last follow-up, 93 stems (99%) were biologically stable and one stem (1%) was revised because of loosening. No hip had distal diaphyseal osteolysis. Proximal femoral stress-shielding was reported in 86 hips (91%). We found no significant relationship between collar-calcar contact and thigh pain, stem fixation status, or stress-shielding. The cumulative survival of the femoral stem was 99% (95% confidence interval, 98-100%) after 10 years.
The long-term results of total hip arthroplasty using a second-generation cementless femoral prosthesis with a collar and straight distal fixation channels were satisfactory; however, the high rate of proximal stress-shielding and the minimal effect of the collar indicate the need for some changes in the stem design.
Total hip arthroplasty; second-generation; cementless; collar; straight distal fixation channel
To evaluate the evidence supporting the effectiveness of acupuncture treatment for SCI and its complications, we conducted search across 19 electronic databases to find all of the randomized controlled trials (RCTs) that used acupuncture as a treatment for SCI and its complications. The methodological quality of each RCT was assessed using the Cochrane risk of bias tool and the PEDro scale. Sixteen RCTs, including 2 high-quality RCTs, met our inclusion criteria (8 for functional recovery from SCI, 6 for bladder dysfunction, and 2 for pain control). The meta-analysis showed positive results for the use of acupuncture combined with conventional treatments for the functional recovery in terms of motor ASIA scores and total FIM scores when compared to conventional treatments alone. Positive results were also obtained for the treatment of bladder dysfunction, in terms of the total efficacy rate, when comparing acupuncture to conventional treatments. However, 2 RCTs for pain control reported conflicting results. Our systematic review found encouraging albeit limited evidence for functional recovery, bladder dysfunction, and pain in SCI. However, to obtain stronger evidence without the drawbacks of trial design and the quality of studies, we recommend sham-controlled RCTs or comparative effectiveness research for each condition to test the effectiveness of acupuncture.
Although polymers, polyplexes, and cells are exposed to various extracellular and intracellular pH environments during polyplex preparation and polymeric transfection, the impact of environmental pH on polymeric transfection has not yet been investigated. This study aims to understand the influence of environmental pH on polymeric transfection by modulating the pH of the transfection medium or the culture medium. Changes in the extracellular pH affected polymeric transfection by way of complex factors such as pH-induced changes in polymer characteristics (e.g., proton buffering capacity and ionization), polyplex characteristics (e.g., size, surface charge, and decomplexation), and cellular characteristics (e.g., cellular uptake, cell cycle phases, and intracellular pH environment). Notably, acidic medium delayed endocytosis, endosomal acidification, cytosolic release, and decomplexation of polyplexes, thereby negatively affecting gene expression. However, acidic medium inhibited mitosis and reduced dilution of gene expression, resulting in increased transfection efficiency. Compared to pH 7.4 medium, acidic transfection medium reduced gene expression 1.6~7.7-fold whereas acidic culture medium enhanced transfection efficiency 2.1~2.6-fold. Polymeric transfection was affected more by the culture medium than by the transfection medium. Understanding the effects of extracellular pH during polymeric transfection may stimulate new strategies for determining effective and safe polymeric gene carriers.
Cytosolic phospholipase A2α (cPLA2α) is a rate-limiting key enzyme controlling the release of arachidonic acid (AA) substrate for the synthesis of prostaglandins and leukotrienes. This study was designed to explore the role of hepatocyte cPLA2α in Fas-mediated liver injury, in vivo.
Transgenic mice with targeted expression of cPLA2α under control of the albumin-promoter enhancer and wild-type mice were injected intraperitoneally with anti-Fas antibody Jo2 or lipopolysaccharide plus D-galactosamine and monitored for liver injury and survival at various time points.
The cPLA2α Tg mice resist Fas-induced liver failure, as reflected by the lower serum transaminase levels, fewer apoptotic hepatocytes, reduced caspase activation, and reduced PARP cleavage when compared to the matched wild type mice. Inhibition of cPLA2α by its pharmacological inhibitor, pyrrolidine, enhanced Jo2-induced liver injury in both cPLA2α Tg and wild type mice. Hepatic overexpression of cPLA2α increases the expression of EGFR in the liver and the EGFR inhibitor, AG1478, exacerbated Jo2-mediated liver injury. The cPLA2α transgenic mice develop more prominent liver tissue damage than wild-type mice after LPS/D-galactosamine injection.
Hepatocyte cPLA2α protects against Fas-induced liver injury and this effect is mediated at least in part through upregulation of EGFR.
Cytosolic phospholipase A2; liver; Fas; apoptosis; epidermal growth factor receptor; LPS
Obesity is characterized by chronic inflammation of adipose tissue, which contributes to insulin resistance and diabetes. Although nitric oxide (NO) signaling has anti-inflammatory effects in the vasculature, whether reduced NO contributes to adipose tissue inflammation is unknown. We sought to determine whether 1) obesity induced by high-fat (HF) diet reduces endothelial nitric oxide signaling in adipose tissue, 2) reduced endothelial nitric oxide synthase (eNOS) signaling is sufficient to induce adipose tissue inflammation independent of diet, and 3) increased cGMP signaling can block adipose tissue inflammation induced by HF feeding.
Methods and results
Relative to mice fed a low-fat diet, HF diet markedly reduced phospho-eNOS and phospho-VASP, markers of vascular NO signaling. Expression of pro-inflammatory cytokines was increased in adipose tissue of eNOS−/− mice. Conversely, enhancement of signaling downstream of NO by phosphodiesterase 5 (PDE-5) inhibition using sildenafil attenuated HF-induced pro-inflammatory cytokine expression and the recruitment of macrophages into adipose tissue. Finally, we implicate a role for Vasodilator- stimulated phosphoprotein (VASP), a downstream mediator of NO-cGMP signaling in mediating eNOS-induced anti-inflammatory effects since VASP−/− mice recapitulated the pro-inflammatory phenotype displayed by eNOS−/− mice.
These results imply a physiological role for endothelial NO to limit obesity-associated inflammation in adipose tissue and hence identifies the NO-cGMP-VASP pathway as a potential therapeutic target in the treatment of diabetes.
This study analyzed the type of acute urinary retention (AUR) and evaluated the treatments used, including trial without catheter (TWOC).
Materials and Methods
This study was based on 299 patients who were treated for AUR from January 2007 to August 2009. The patients were classified into the spontaneous AUR group (group S) and the precipitated AUR group (group P), in which AUR was consecutive to triggering events. The treatment modalities including TWOC, the success rate of TWOC, age, prostate-specific antigen (PSA) levels, the volume of the prostate, and the drained volume at catheterization were analyzed in each group.
Of 299 men with AUR, 160 (54%) had spontaneous AUR and 139 (46%) had precipitated AUR. Compared with group P, patients in group S were more likely to be treated by surgery, either immediately (16.9% vs. 3.6%, p<0.05) or after prolonged catheterization (42.2% vs. 29.1%, p<0.05). The success rate of TWOC was lower in men of older ages (≥70 years) and in those with enlarged prostates (≥50 ml), higher PSA levels (≥3 ng/ml), and a large drained volume at catheterization (≥1,000 ml).
In this group of AUR patients, there were slightly more patients with spontaneous AUR (54%) than with precipitated AUR (46%). The success rate of TWOC was more than 70% regardless of the type of AUR. Although TWOC is recommended primarily in the treatment of AUR, early surgical intervention should be considered if the patient has an enlarged prostate (≥50 ml) or a large drained volume at catheterization (≥1,000 ml).
Prostatic hyperplasia; Urinary catheterization; Urinary retention
Docosahexaenoic acid (DHA) has been reported to induce tumor cell death by apoptosis. However, little is known about the effects of DHA on autophagy, another complex well-programmed process characterized by the sequestration of cytoplasmic material within autophagosomes. Here we show that DHA increased both the level of microtubule-associated protein 1 light chain 3 and the number of autophagic vacuoles without impairing autophagic vesicle turnover, indicating that DHA induces not only apoptosis but also autophagy. We also observed that DHA-induced autophagy was accompanied by p53 loss. Inhibition of p53 increased DHA-induced autophagy and prevention of p53 degradation significantly led to the attenuation of DHA-induced autophagy, suggesting that DHA-induced autophagy is mediated by p53. Further experiments showed that the mechanism of DHA-induced autophagy associated with p53 attenuation involved an increase in the active form of AMP-activated protein kinase and a decrease in the activity of mammalian target of rapamycin. In addition, compelling evidence for the interplay between autophagy and apoptosis induced by DHA is supported by the findings that autophagy inhibition suppressed apoptosis and further autophagy induction enhanced apoptosis in response to DHA treatment. Overall, our results demonstrate that autophagy contributes to the cytotoxicity of DHA in cancer cells harboring wild-type p53.
DHA; autophagy; apoptosis; p53; cancer; mTOR; AMPK; p27
Microsomal prostaglandin E synthase-1 (mPGES-1) is a key enzyme that couples with cyclooxygenase-2 (COX-2) for the production of PGE2. Although COX-2 is known to mediate the growth and progression of several human cancers including hepatocellular carcinoma (HCC), the role of mPGES-1 in hepatocarcinogenesis is not well established. This study provides novel evidence for a key role of mPGES-1 in HCC growth and progression. Forced overexpression of mPGES-1 in two HCC cell lines (Hep3B and Huh7) increased tumor cell growth, clonogenic formation, migration and invasion, whereas knockdown of mPGES-1 inhibited these parameters, in vitro. In a SCID mouse tumor xenograft model, mPGES-1 overexpressed cells formed palpable tumors at earlier time points and developed larger tumors when compared to the control (p<0.01); in contrast, mPGES-1 knockdown delayed tumor development and reduced tumor size (p<0.01). Mechanistically, mPGES-1-induced HCC cell proliferation, invasion and migration involve PGE2 production and activation of early growth response 1 (EGR1) and β-catenin. Specifically, mPGES-1-derived PGE2 induces the formation of EGR1-β-catenin complex, which interacts with TCF4/LEF1 transcription factors and activates the expression of β-catenin downstream genes. Our findings depict a novel crosstalk between mPGES-1/PGE2 and EGR1/β-catenin signaling that is critical for hepatocarcinogenesis.
Microsomal prostaglandin E synthase-1 (mPGES-1); β-catenin; early growth response 1 (EGR1); hepatocellular carcinoma (HCC); liver
Reactive oxygen species and inflammatory responses contribute to the development of neuropathic pain. Superoxide serves to mediate cell signaling processes and tissue injury during inflammation. We examined the effects of superoxide on the development and maintenance of mechanical allodynia, as well as its contribution to central sensitization in a superoxide-rich animal model of neuropathic pain.
Chronic post-ischemia pain (CPIP) was induced via the left hindpaw ischemia for 3 h, followed by reperfusion. Superoxide dismutase (4,000 U/kg, i.p.) was administered either 5 min before ischemia (BI), 5 min before reperfusion (BR), or 3 days after reperfusion (3AR). Withdrawal thresholds of the four paws were measured to assess the mechanical allodynia and the effects of circulating xanthine oxidase (XO)-mediated superoxide production. In addition, we measured the levels of N-methyl D-aspartate receptor subunit 1 phosphorylation (p-NR1) in the ipsilateral and contralateral spinal cord (L4-6), by Western blotting, to examine the superoxide-mediated central sensitization. Superoxide production was assessed by allopurinol-sensitive, XO-mediated lipid peroxidation of the spinal cord and gastrocnemius muscles.
Withdrawal thresholds of forepaws did not vary across the 7 days of testing. In the hindpaws, both ipsilateral and contralateral mechanical allodynia was most attenuated in the BR group, followed by the BI and 3AR groups. The degree of NR1 activation was in contrast to the changes in the withdrawal thresholds.
These data suggest that superoxide is involved in the development and maintenance of mechanical allodynia, particularly via central sensitization in the spinal cord.
Chronic post-ischemia pain; Complex regional pain syndrome; Mechanical allodynia; Neuropathic pain; Reactive oxygen species; Superoxide
Numerous studies have demonstrated adaptive behavioral responses of males and females to changes in operational sex ratio (the ratio of potentially receptive males to receptive females; OSR), and theory often assumes that animals have perfect instantaneous knowledge about the OSR. However, the role of sensory mechanisms in monitoring the local sex ratio by animals and whether animals can perceive local sex ratio in a manner consistent with model assumptions have not been well addressed. Here, we show that mating water striders Gerris gracilicornis respond to local sex ratio even when visual and physical contact with other individuals were experimentally prohibited. Our study shows that insects are able to estimate local population’s sex ratio and adjust their behavior based on nonvisual cues perceived at a distance or released to the habitat. Hence, the frequent theoretical assumption that individuals have knowledge about their local sex ratio regardless of their direct behavioral interactions may be an acceptable approximation of reality.
Sex ratio; Chemical cues; Ripple signals; Mating interactions; Sex recognition
Cationic polymers are potential intracellular carriers for small interfering RNA (siRNA). The short and rigid nature of an siRNA chain often results in larger and more loosely packed particles compared to plasmid DNA (pDNA) after complexing with carrier polycations, and in turn, poor silencing effects are seen against the target mRNAs. A helper polyanion, pDNA, was incorporated along with siRNA to form compact nanosized polyplexes. At C/A (cation/anion) ratios of 2 and 5, poly(L-lysine) (PLL)/siRNA-pGFP and PLL/siRNA-pGFP-OSDZ (oligomeric sulfadiazine (OSDZ) for endosomolysis) complexes produced particles 90–150 nm in size with a 15–45 mV surface charge, while PLL/siRNA complexes yielded particles 1–2 μm in size at the same C/A ratios. The PLL/siRNA-pGFP (C/A 2) complexes showed significantly higher specific gene silencing (50–90% vs. 10–25%) than the complexes formed at C/A 5. PLL/siRNA-pGFP-OSDZ (C/A 2) complexes improved the specific gene silencing (90%) more dramatically than PLL/siRNA-pGFP (C/A 2) complexes (50%), demonstrating a potential role for OSDZ. PLL/siRNA-pGFP-OSDZ (C/A 2) complexes sustained higher specific gene silencing compared with PLL/siRNA-pGFP (C/A 2) complexes. Other oligomeric sulfonamides (OSA) with varying pKa used in PLL/siRNA-pGFP-OSA complexes also caused effective gene silencing. The pGFP in the PLL/siRNA-pGFP complexes successfully expressed GFP protein without interfering with the siRNA. In conclusion, this study demonstrates that long pDNA helps effectively form nanosized siRNA particles and that OSA enhances specific gene silencing. In a single nucleic acid carrier formulation, co-delivery of siRNA and pDNA is feasible to maximize therapeutic effects or to include therapeutic or diagnostic functionalities.
Background & Aims
Microsomal prostaglandin E synthase-1 (mPGES-1) is a rate-limiting enzyme that is coupled with cyclooxygenase-2 (COX-2) in the synthesis of prostaglandin E2 (PGE2). Although COX-2 is involved in development and progression of various human cancers, the role of mPGES-1 in carcinogenesis has not been determined. We investigated the role of mPGES-1 in human cholangiocarcinoma growth.
We used immunohistochemical analyses to examine the expression of mPGES-1 in formalin-fixed, paraffin-embedded human cholangiocarcinoma tissues. The effects of mPGES-1 on human cholangiocarcinoma cells were determined in vitro and in SCID mice. Immunoblotting and immunoprecipitation assays were performed to determine the levels of PTEN and related signaling molecules in human cholangiocarcinoma cells with overexpression or knockdown of mPGES-1.
mPGES-1 is overexpressed in human cholangiocarcinoma tissues. Overexpression of mPGES-1 in human cholangiocarcinoma cells increased tumor cell proliferation, migration, invasion, and colony formation; in contrast, RNAi knockdown of mPGES-1 inhibited tumor growth parameters. In SCID mice with tumor xenografts, mPGES-1 overexpression accelerated tumor formation and increased tumor weight (P<0.01), whereas mPGES-1 knockdown delayed tumor formation and reduced tumor weight (P<0.01). mPGES-1 inhibited the expression of PTEN, leading to activation of the EGFR–PI3K–AKT–mTOR signaling pathways in cholangiocarcinoma cells. mPGES-1–mediated inhibition of PTEN is regulated through blocking of EGR-1 sumoylation and binding to the 5′-UTR of the PTEN gene.
mPGES-1 promotes experimental cholangiocarcinogenesis and tumor progression by inhibiting PTEN.
cancer cell signaling; biliary tract cancer; bile duct; liver
This study investigated the potential of creating a charged polymeric micelle-based nucleic acid delivery system that could easily be reconstituted by the addition of water. (PLGA36kDa)2-b-bPEI25kDa (PLGA MW 36kDa, bPEI Mw 25kDa, PLGA:bPEI block ratio = 2) was synthesized and used to prepare cationic micelles. The copolymer retained proton-buffering capability from the bPEI block within the endosomal pH range. Micelle/pDNA complexes retained their particle size (100–150 nm) and surface charge (30–40 mV) following reconstitution. It was found that adding a small amount of low molecular weight bPEI (1.8 kDa) completely shielded pDNA in the micelle/pDNA complexes and enhanced transfection efficiency 50–100 fold for both fresh and reconstituted complexes without affecting complex size. Transfection efficiency for “reconstituted” micelle/pDNA/bPEI1.8kDa (WR 1) complexes was 16-fold higher than its “fresh” counterpart. Although transfection levels achieved using “reconstituted” micelle/pDNA/bPEI1.8kDa complexes were 3.6-fold lower than control “fresh” bPEI25kDa/pDNA (N/P 5) complexes, transfection levels were 39-fold higher than “reconstituted” bPEI25kDa/pDNA (N/P 5) complexes. The micelle/pDNA/bPEI1.8kDa system showed very low cytotoxicity in MCF7 cells even with pDNA doses up to 20 μg, and transfection levels increased linearly with increasing pDNA dose. These results indicate that this PLGA-b-bPEI polymeric micelle-based system is well suited as a reconstitutable gene delivery system, and has high potential for use as a delivery system for gene therapy applications.
In the title trinuclear NiII compound, [Ni3(C18H19N2O3)2(C5H5N)4]·C3H7NO·H2O, three NiII cations are bridged by two N′-(adamantan-1-ylcarbonyl)-2-oxidobenzohydrazidate trianions. The central NiII cation has a distorted octahedral N4O2 coordination environment where a reverse torsion occurs between the two bridging ligands, whereas the two NiII cations on the sides each adopt an N2O2 square-planar coordination. Weak intramolecular C—H⋯O and C—H⋯N interactions help to stabilize the molecular structure. In the crystal, the lattice water molecule links with the NiII complex and dimethylformamide solvent molecule via O—H⋯O hydrogen bonding.
An intravenous infusion of lidocaine has been used on numerous occasions to produce analgesia in neuropathic pain. In the cases of failed back surgery syndrom, the pain generated as result of abnormal impulse from the dorsal root ganglion and spinal cord, for instance as a result of nerve injury may be particularly sensitive to lidocaine. The aim of the present study was to identify the effects of IV lidocaine on neuropathic pain items of FBSS.
The study was a randomized, prospective, double-blinded, crossover study involving eighteen patients with failed back surgery syndrome. The treatments were: 0.9% normal saline, lidocaine 1 mg/kg in 500 ml normal saline, and lidocaine 5 mg/kg in 500 ml normal saline over 60 minutes. The patients underwent infusions on three different appointments, at least two weeks apart. Thus all patients received all 3 treatments. Pain measurement was taken by visual analogue scale (VAS), and neuropathic pain questionnaire.
Both lidocaine (1 mg/kg, 5 mg/kg) and placebo significantly reduced the intense, sharp, hot, dull, cold, sensitivity, itchy, unpleasant, deep and superficial of pain. The amount of change was not significantly different among either of the lidocaine and placebo, or among the lidocaine treatments themselves, for any of the pain responses, except sharp, dull, cold, unpleasant, and deep pain. And VAS was decreased during infusion in all 3 group and there were no difference among groups.
This study shows that 1 mg/kg, or 5 mg/kg of IV lidocaine, and palcebo was effective in patients with neuropathic pain attributable to FBSS, but effect of licoaine did not differ from placebo saline.
failed back surgery syndrome; neuropathic pain; pain quality; systemic lidociane
The fruit hull of Gleditsia sinensis (FGS) has been prescribed as a traditional eastern Asian medicinal remedy for the treatment of various respiratory diseases, but the efficacy and underlying mechanisms remain poorly characterized. Here, we explored a potential usage of FGS for the treatment of acute lung injury (ALI), a highly fatal inflammatory lung disease that urgently needs effective therapeutics, and investigated a mechanism for the anti-inflammatory activity of FGS. Pretreatment of C57BL/6 mice with FGS significantly attenuated LPS-induced neutrophilic lung inflammation compared to sham-treated, inflamed mice. Reporter assays, semiquantitative RT-PCR, and Western blot analyses show that while not affecting NF-κB, FGS activated Nrf2 and expressed Nrf2-regulated genes including GCLC, NQO-1, and HO-1 in RAW 264.7 cells. Furthermore, pretreatment of mice with FGS enhanced the expression of GCLC and HO-1 but suppressed that of proinflammatory cytokines in including TNF-α and IL-1β in the inflamed lungs. These results suggest that FGS effectively suppresses neutrophilic lung inflammation, which can be associated with, at least in part, FGS-activating anti-inflammatory factor Nrf2. Our results suggest that FGS can be developed as a therapeutic option for the treatment of ALI.
A closely-linked pair of Ac/Ds elements induces chromosomal rearrangements in Arabidopsis and maize. This report summarizes the Ac/Ds systems that generate an exceptionally high frequency of chromosomal rearrangements in rice genomes. From a line containing a single Ds element inserted at the OsRLG5 locus, plants containing a closely-linked pair of inversely-oriented Ds elements were obtained at 1% frequency among the population regenerated from tissue culture. Subsequent regeneration of the lines containing cis-paired Ds elements via tissue culture led to a high frequency (35.6%) of plants containing chromosomal rearrangements at the OsRLG5 locus. Thirty-four rearrangement events were characterized, revealing diverse chromosomal aberrations including deletions, inversions and duplications. Many rearrangements could be explained by sister chromatid transposition (SCT) and homologous recombination (HR), events previously demonstrated in Arabidopsis and maize. In addition, novel events were detected and presumably generated via a new alternative transposition mechanism. This mechanism, termed single chromatid transposition (SLCT), resulted in juxtaposed inversions and deletions on the same chromosome. This study demonstrated that the Ac/Ds system coupled with tissue culture-mediated plant regeneration could induce higher frequencies and a greater diversity of chromosomal rearrangements than previously reported.
Understanding transposon-induced chromosomal rearrangements can provide new insights into the relationship between transposable elements and genome evolution, as well as a means to perform chromosomal engineering for crop improvement. Rice is a staple cereal crop worldwide. Complete genome sequencing and rich genetic resources are great advantages for the study of the genomic complexity induced by transposable elements.1–2 The combination of tissue culture with genetic lines carrying a pair of closely located Ac/Ds elements greatly increases the frequency and diversity of rearrangements in rice genomes. The methodology and its efficiency and significance are briefly summarized.
Ac/Ds element; SLCT; chromosomal rearrangements; regeneration; rice; transposition
To improve transfection efficiency and reduce the cytotoxicity of polymeric gene vectors, reducible polycations (RPC) were synthesized from low molecular weight (MW) branched polyethyleneimine (bPEI) via thiolation and oxidation. RPC (RPC-bPEI0.8kDa) possessed a MW of 5 kDa~80 kDa, and 50%~70% of the original proton buffering capacity of bPEI0.8kDa was preserved in the final product. The cytotoxicity of RPC-bPEI0.8kDa was 8~19 times less than that of the gold standard of polymeric transfection reagents, bPEI25kDa. Although bPEI0.8kDa exhibited poor gene condensing capacities (~2 µm at a weight ratio (WR) of 40), RPC-bPEI0.8kDa effectively condensed plasmid DNA (pDNA) at a WR of 2. Moreover, RPC-bPEI0.8kDa/pDNA (WR ≥ 2) formed 100~200 nm-sized particles with positively charged surfaces (20~35 mV). In addition, the results of the present study indicated that thiol/polyanions triggered the release of pDNA from RPC-bPEI0.8kDa/pDNA via the fragmentation of RPC-bPEI0.8kDa and ion-exchange. With negligible polyplex-mediated cytotoxicity, the transfection efficiencies of RPC-bPEI0.8kDa/pDNA were approximately 1200~1500-fold greater than that of bPEI0.8kDa/pDNA and were equivalent or superior (~7-fold) to that of bPEI25kDa/pDNA. Interestingly, the distribution of high MW RPC-bPEI0.8kDa/pDNA in the nucleus of the cell was higher than that of low MW RPC-bPEI0.8kDa/pDNA. Thus, the results of the present study suggest that RPC-bPEI0.8kDa has the potential to effectively deliver genetic materials with lower levels of toxicity.
Colloidal III-V semiconductor nanocrystal quantum dots [NQDs] have attracted interest because they have reduced toxicity compared with II-VI compounds. However, the study and application of III-V semiconductor nanocrystals are limited by difficulties in their synthesis. In particular, it is difficult to control nucleation because the molecular bonds in III-V semiconductors are highly covalent. A synthetic approach of InP NQDs was presented using newly synthesized organometallic phosphorus [P] precursors with different functional moieties while preserving the P-Si bond. Introducing bulky side chains in our study improved the stability while facilitating InP formation with strong confinement at a readily low temperature regime (210°C to 300°C). Further shell coating with ZnS resulted in highly luminescent core-shell materials. The design and synthesis of P precursors for high-quality InP NQDs were conducted for the first time, and we were able to control the nucleation by varying the reactivity of P precursors, therefore achieving uniform large-sized InP NQDs. This opens the way for the large-scale production of high-quality Cd-free nanocrystal quantum dots.
phosphorus precursor; indium phosphide nanocrystal quantum dot; colloidal synthesis; nontoxic
Cadherins mediate cell-cell adhesion and catenin (ctn)-related signaling pathways. Liver fibrosis is accompanied by the loss of E-cadherin (ECAD), which promotes the process of epithelial-mesenchymal transition. Currently, no information is available about the inhibitory role of ECAD in hepatic stellate cell activation. Because of ECAD’s potential for inhibiting the induction of transforming growth factor β1 (TGFβ1), we investigated whether ECAD overexpression prevents TGFβ1 gene induction; we also examined what the molecular basis could be. Forced expression of ECAD decreased α-smooth muscle actin and vimentin levels and caused decreases in the constitutive and inducible expression of the TGFβ1 gene and its downstream genes. ECAD overexpression decreased Smad3 phosphorylation, weakly decreased Smad2 phosphorylation, and thus inhibited Smad reporter activity induced by either treatment with TGFβ1 or Smad3 overexpression. Overexpression of a dominant negative mutant of ras homolog gene family A (RhoA) diminished the ability of TGFβ1 to elicit its own gene induction. Consistently, transfection with a constitutively active mutant of RhoA reversed the inhibition of TGFβ1-inducible or Smad3-inducible reporter activity by ECAD. Studies using the mutant constructs of ECAD revealed that the p120-ctn binding domain of ECAD was responsible for TGFβ1 repression. Consistently, ECAD was capable of binding p120-ctn, which recruited RhoA; this prevented TGFβ1 from increasing RhoA-mediated Smad3 phosphorylation. In the liver samples of patients with mild or severe fibrosis, ECAD expression reciprocally correlated with the severity of fibrosis.
Our results demonstrate that ECAD inhibits Smad3/2 phosphorylation by recruiting RhoA to p120-ctn at the p120-ctn binding domain, whereas the loss of ECAD due to cadherin switching promotes the up-regulation of TGFβ1 and its target genes, and facilitates liver fibrosis.
In the title complex, [CuCl2(C24H24N2O2)], the CuII cation is N,N′,O-chelated by a 2,2′-(1,1′-binaphthyl-2,2′-diyldiimino)diethanol ligand and coordinated by two chloride anions in a distorted square-pyramidal geometry. In the diethanol ligand, the two naphthalene ring systems are twisted with respect to each other at a dihedral angle of 68.30 (9)°. The uncoordinated hydroxy group links with a coordinated chloride anion via an intramolecular O—H⋯Cl hydrogen bond. Intermolecular N—H⋯O and N—H⋯Cl hydrogen bonds occur in the crystal structure.
Previous studies have shown that pairs of closely-linked Ac/Ds transposable elements can induce various chromosomal rearrangements in plant genomes. To study chromosomal rearrangements in rice, we isolated a line (OsRLG5-161) that contains two inversely-oriented Ds insertions in OsRLG5 (Oryza sativa Receptor like kinase Gene 5). Among approximately 300 plants regenerated from OsRLG5-161 heterozygous seeds, 107 contained rearrangements including deletions, duplications and inversions of various sizes. Most rearrangements were induced by previously identified alternative transposition mechanism. Furthermore, we also detected a new class of rearrangements that contain juxtaposed inversions and deletions on the same chromosome. We propose that these novel alleles were generated by a previously unreported type of alternative transposition reactions involving the 5′ and 3′ termini of two inversely-oriented Ds elements located on the same chromatid. Finally, 11% of rearrangements contained inversions resulting from homologous recombination between the two inverted Ds elements in OsRLG5-161. The high frequency inheritance and great variety of rearrangements obtained suggests that the rice regeneration system results in a burst of transposition activity and a relaxation of the controls which normally limit the transposition competence of individual Ds termini. Together, these results demonstrate a greatly enlarged potential of the Ac/Ds system for plant chromosome engineering.
Epigenetic modifications like DNA methylation and histone acetylation play an important role in a wide range of brain disorders. Histone deacetylases (HDACs) regulate the homeostasis of histone acetylation. Histone deacetylase inhibitors, which initially were used as anticancer drugs, are recently suggested to act as neuroprotectors by enhancing synaptic plasticity and learning and memory in a wide range of neurodegenerative and psychiatric disorders, such as Alzheimer's disease (AD) and Parkinson's disease (PD). To reveal the physiological roles of HDACs may provide us with a new perspective to understand the mechanism of AD and to develop selective HDAC inhibitors. This paper focuses on the recent research progresses of HDAC proteins and their inhibitors on the roles of the treatment for AD.