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This study developed methodologies for rapid screening and analysis of numerous biological samples following a radiation accident. A measurement system was established to determine the presence of internal contamination promptly. Smear screening method could distinguish contaminated patients by setting a 20% buffer zone. Gross alpha and gross beta screening method could distinguish contaminated patients by setting limit of detection (0.70, 393 cpm). Smear screening, gross alpha screening, and gross beta screening methodologies are expected to detect internal contamination quickly. While effective for screening, these methods were unsuitable for precise analysis. [ABSTRACT FROM AUTHOR]

Tendons are responsible for transmitting mechanical forces from muscles to bones for body locomotion and joint stability. However, tendons are frequently damaged with high mechanical forces. Various methods have been utilized for repairing damaged tendons, including sutures, soft tissue anchors, and biological grafts. However, tendons experience a higher rate of retear post-surgery due to their low cellularity and vascularity. Surgically sutured tendons are vulnerable to reinjury due to their inferior functionality when compared with native tendons. Surgical treatment using biological grafts also has complications such as joint stiffness, re-rupture, and donor-site morbidity. Therefore, current research is focused on developing novel materials that can facilitate the regeneration of tendons with histological and mechanical characteristics similar to those of intact tendons. With respect to the complications in association with the surgical treatment of tendon injuries, electrospinning may be an alternative for tendon tissue engineering. Electrospinning is an effective method for fabrication of polymeric fibers with diameters ranging from nanometers to micrometers. Thus, this method produces nanofibrous membranes with an extremely high surface area-to-volume ratio, which is similar to the extracellular matrix structure, making them suitable candidates for application in tissue engineering. Moreover, it is possible to fabricate nanofibers with specific orientations that are similar to those of the native tendon tissue using an adequate collector. To increase the hydrophilicity of the electrospun nanofibers, natural polymers in addition to synthetic polymers are used concurrently. Therefore, in this study, aligned nanofibers composed of poly-d,l-lactide-co-glycolide (PLGA) and small intestine submucosa (SIS) were fabricated using electrospinning with rotating mandrel. The diameter of aligned PLGA/SIS nanofibers was 568.44 ± 135.594 nm, which closely resembles that of native collagen fibrils. Compared to the results of the control group, the mechanical strength exhibited by the aligned nanofibers was anisotropic in terms of break strain, ultimate tensile strength, and elastic modulus. Elongated cellular behavior was observed in the aligned PLGA/SIS nanofibers using confocal laser scanning microscopy, indicating that the aligned nanofibers were highly effective with regard to tendon tissue engineering. In conclusion, considering its mechanical properties and cellular behavior, aligned PLGA/SIS is a promising candidate for tendon tissue engineering. [ABSTRACT FROM AUTHOR]

The threat of arsenic contamination to public health, particularly in developing countries, has become a serious problem. Millions of people in their daily lives are still highly dependent on groundwater containing high levels of arsenic, which causes excessive exposure to this toxic element, due to the high cost and lack of water-treatment infrastructures. Therefore, a technique for large-scale treatment of water in rural areas to remove arsenic is needed and should be low-cost, be easily customized, and not rely on electrical power. In this study, in an effort to fulfill those requirements, we introduce a three-dimensional (3D), printed water-filtration system for arsenic removal. Three-dimensional printing can provide a compact, customized filtration system that can fulfill the above-mentioned requirements and that can be made from plastic materials, which are abundant. Armed with the versatility of 3D printing, we were able to design the internal surface areas of filters, after which we modified the surfaces of the 3D, printed filters by using iron (III) oxide as an adsorbent for arsenite. We investigated the effects of the controlled surface area on the flow rate and the deposition of the adsorbent, which are directly related to the adsorption of arsenic. We conducted isotherm studies to quantify the adsorption of arsenic on our 3D, printed filtration system. [ABSTRACT FROM AUTHOR]

• Rubbery SBS-g-POEM amphiphilic copolymer showed excellent compatibility with ZIF-8. • MMMs with SBS showed a continuous decrease in selectivity. • MMMs with SBS-g-POEM achieved simultaneous improvement in permeability and selectivity. • MMMs exhibited good mechanical strength and excellent thermal stability up to 300 °C. We report the development and assessment of mixed-matrix membranes (MMMs) that showed simultaneous improvement in CO 2 permeability and CO 2 /N 2 selectivity based on precise interface and interaction control. Specifically, MMMs were prepared using solution-synthesized ZIF-8 nanoparticles dispersed in a rubbery amphiphilic copolymer matrix, namely, poly(styrene- b -butadiene- b -styrene)- g -poly(oxyethylene methacrylate) (SBS-g-POEM) synthesized by free-radical polymerization. Excellent interface contact and compatibility between the ZIF-8 nanoparticles and SBS-g-POEM matrix were confirmed. The results showed that the polymer matrix did not damage the nanostructure of the ZIF-8, and the POEM chains grafted from the SBS backbones enhanced the compatibility with the ZIF-8. While the MMM based on a neat SBS matrix showed a continuous decrease in selectivity, the MMM based on SBS-g-POEM achieved a simultaneous improvement in permeability (from 261.7 to 522.3 Barrer) and CO 2 /N 2 selectivity (from 18.6 to 20.8), indicating the importance of the matrix in tuning the interface and interaction of MMMs. The obtained CO 2 /N 2 separation performance is close to the upper bound and one of the highest values for ZIF-8-based MMMs. Furthermore, the MMMs exhibited good mechanical strength (8.5 MPa tensile stress and 940% strain) and excellent thermal stability at least up to 300 °C. [ABSTRACT FROM AUTHOR]

Owing to their novel optical properties, three-dimensionalplasmonicnanostructures with reduced symmetry such as a nanocrescent and ananocup have attracted considerable current interest in biophotonicimaging and sensing. However, their practical applications have beenstill limited since the colloidal synthesis of such structures thatallows, in principle, for in vivo application and large-scale productionhas not been explored yet. To date, these structures have been fabricatedonly on two-dimensional substrates using micro/nanofabrication techniques.Here we demonstrate an innovative way of breaking symmetry of colloidalplasmonic nanoparticles. Our strategy exploits the direct overgrowthof Au on a hybrid colloidal dimer consisting of Au and polystyrene(PS) nanoparticles without the self-nucleation of Au in an aqueoussolution. Upon the overgrowth reaction, the steric crowding of PSleads to morphological evolution of the Au part in the dimer rangingfrom half-shell, nanocrescent to nanoshell associated with the appearanceof the second plasmon absorption band in near IR. Surface-enhancedRaman scattering signal is obtained directly from the symmetry-brokennanoparticles solution as an example showing the viability of thepresent approach. We believe our concept represents an important steptoward a wide range of biophotonic applications for optical nanoplasmonicssuch as targeting, sensing/imaging, gene delivery, and optical generegulations. [ABSTRACT FROM AUTHOR]

Abstract: Chromatin structure is modulated during transcriptional activation. The changes include the association of transcriptional activators, formation of hypersensitive sites and covalent modifications of histones. To understand the order of the various changes accompanying transcriptional activation, we analyzed the mouse β globin gene, which is transcriptionally inducible in erythroid MEL cells over a time course of HMBA treatment. Transcription of the globin genes requires the locus control region (LCR) consisting of several hypersensitive sites (HSs). Erythroid specific transcriptional activators such as NF-E2, GATA-1, TAL1 and EKLF were associated with the LCR in the uninduced state before transcriptional activation. The HSs of the LCR were formed in this state as revealed by high sensitivity to DNase I and MNase attack. However the binding of transcriptional activators and the depletion of histones were observed in the promoter of the β globin gene only after transcriptional activation. In addition, various covalent histone modifications were sequentially detected in lysine residues of histone H3 during the activation. Acetylation of K9, K36 and K27 was notable in both LCR HSs and gene after induction but before transcriptional initiation. Inactive histone marks such as K9me2, K36me2 and K27me2 were removed coincident with transcriptional initiation in the gene region. Taken together, these results indicate that LCR has a substantially active structure in the uninduced state while transcriptional activation serially adds active marks, including histone modifications, and removes inactive marks in the target gene of the LCR. [ABSTRACT FROM AUTHOR]

Enhancers cause a high level of transcription and activation of chromatin structure at target genes. Hyperacetylation of histones H3 and H4, a mark of active chromatin, is established broadly across target loci by enhancers that function over long distances. In the present study, we studied the role of an enhancer in methylation of various lysine residues on H3 by comparing a model gene locus having an active enhancer with one in which the enhancer has been inactivated within the context of minichromosomes. The intact enhancer affected histone methylation at K4, K9 and K36 in distinct ways depending on the methylation level and the location in the locus. All three lysine residues were highly tri-methylated in the coding region of the gene linked to the active enhancer but not the inactive enhancer. However di-methylation of K9 and K36 was not affected by the enhancer. The enhancer region itself was marked by mono-methylation at K4 and K9, distinguishing it from the methyl marks in the gene coding region. These results indicate that an enhancer has roles in establishing active histone methylation patterns linked with gene transcription rather than removing methylation linked with gene inactivation. [ABSTRACT FROM AUTHOR]

Abstract: Ribonuclease P (RNase P) complexed with an external guide sequence (EGS) represents a novel nucleic acid-based gene interference approach to modulate gene expression. This enzyme is a ribonucleoprotein complex for tRNA processing. In Escherichia coli, RNase P contains a catalytic RNA subunit (M1 ribozyme) and a protein subunit (C5 cofactor). EGSs, which are RNAs derived from natural tRNAs, bind to a target mRNA and render the mRNA susceptible to hydrolysis by RNase P and M1 ribozyme. When covalently linked with a guide sequence, M1 can be engineered into a sequence-specific endonuclease, M1GS ribozyme, which cleaves any target RNAs that base pair with the guide sequence. Studies have demonstrated efficient cleavage of mRNAs by M1GS and RNase P complexed with EGSs in vitro. Moreover, highly active M1GS and EGSs were successfully engineered using in vitro selection procedures. EGSs and M1GS ribozymes are effective in blocking gene expression in both bacteria and human cells, and exhibit promising activity for antimicrobial, antiviral, and anticancer applications. In this review, we highlight some recent results using the RNase P-based technology, and offer new insights into the future of using EGS and M1GS RNA as tools for basic research and as gene-targeting agents for clinical applications. [Copyright &y& Elsevier]

RNase P, a tRNA processing enzyme, contains both RNA and protein subunits. M1 RNA, the catalytic RNA subunit of RNase P from Escherichia coil, recognizes its target RNA substrate mainly on the basis of its structure and cleaves a double stranded RNA helix at the 5' end that resembles the acceptor stem and T-stem structure of its natural tRNA substrate. Accordingly, a guide sequence (GS) can be covalently attached to the M1 RNA to generate a sequence specific ribozyme, M1GS RNA. M1GS ribozyme can target any mRNA sequence of choice that is complementary to its guide sequence. Recent studies have shown that M1GS ribozymes efficiently cleave the mRNAs of herpes simplex virus 1 and human cytomegalovirus, and the BCR-ABL oncogenic mRNA in vitro and effectively reduce the expression of these mRNAs in cultured cells. Moreover, an in vitro selection scheme has been developed to select for M1 GS ribozyme variants with more efficient catalytic activity in cleaving mRNAs. When expressed in cultured cells, these selected ribozymes also show an enhance ability to inhibit viral gene expression and growth. These recent results demonstrate the feasibility of developing the M1GS ribozyme-based technology as a promising gene targeting approach for basic research and clinical therapeutic application. [ABSTRACT FROM AUTHOR]

A sequence-specific ribozyme (M1GS RNA) derived from the catalytic RNA subunit of RNase P from Escherichia coli was used to target the mRNA encoding human cytomegalovirus (HCMV) protease (PR), a viral protein that is responsible for the processing of the viral capsid assembly protein. We showed that the constructed ribozyme cleaved the PR mRNA sequence efficiently in vitro. Moreover, a reduction of about 80% in the expression level of the protease and a reduction of about 100-fold in HCMV growth were observed in cells that expressed the ribozyme stably. In contrast, a reduction of less than 10% in the expression of viral protease and viral growth was observed in cells that either did not express the ribozyme or produced a catalytically inactive ribozyme mutant. Further examination of the antiviral effects of the ribozyme-mediated cleavage of PR mRNA indicates that (1) the proteolytic cleavage of the capsid assembly protein is inhibited significantly, and (2) the packaging of the viral genomic DNA into the CMV capsids is blocked. These observations are consistent with the notion that the protease functions to process the capsid assembly protein and is essential for viral capsid assembly. Moreover, our results indicate that the RNase P ribozyme-mediated cleavage specifically reduces the expression of the protease, but not other viral genes examined. Thus, M1GS ribozyme is highly effective in inhibiting HCMV growth by targeting the PR mRNA and may represent a novel class of general gene-targeting agents for the studies and treatment of infections caused by human viruses, including HCMV. [Copyright &y& Elsevier]

• PEGBEM-g-PAEMA graft copolymer is synthesized via free-radical polymerization. • The electrolyte maintained its flexible solid film state for EMIMBF 4 content up to 200%. • The solid capacitors exhibited good bending performance without specific encapsulation. • The capacitors with PEGBEM-g-PAEMA exhibited better performance compared with other polymer/EMIMBF 4 cells. We report a solid electrolyte comprising poly(ethylene glycol) behenyl ether methacrylate-g-poly((2-acetoacetoxy)ethyl methacrylate) (PEGBEM-g-PAEMA) graft copolymer for application to solid-state bendable supercapacitors. The graft copolymer was synthesized via free-radical polymerization, and the electrolytes were fabricated by adding 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF 4). Fourier-transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, X-ray diffraction, small-angle X-ray scattering, and transmission electron microscopy were employed to investigate the chemical, structural, thermal, and morphological properties of the fabricated electrolytes and the compatibility of the two components. The graft copolymer interacted with EMIMBF 4 (the two materials were compatible with each other), and the intruded ionic liquid was well-dispersed through the entire region of the polymer matrix. The fabricated electrolyte maintained its flexible solid film state for EMIMBF 4 content up to 200% without leakage problems. The capacitors were manufactured with porous carbon electrodes and a PEGBEM-g-PAEMA/EMIMBF 4 electrolyte. The capacitors exhibited a capacitance of 55.5F/g, a power density of 900 W/kg, and an energy density of 25 Wh/kg at 1.0 A/g. The capacitors were measured at various bending angles and exhibited good performance without specific encapsulation. According to the results, the newly synthesized PEGBEM-g-PAEMA graft copolymer is a good candidate for a polymer matrix for electrolytes in all-solid-state bendable/flexible supercapacitors. [ABSTRACT FROM AUTHOR]

We report the synthesis of a series of alcohol-soluble comb copolymers, specifically poly(oxyethylene methacrylate)- co -poly(2-(4-benzoyl-3-hydroxy phenoxy) ethyl acrylate) (POM-PBHP), with various compositions, as well as their use in CO 2 capture membranes. The POM-PBHP comb copolymers were synthesized through a low-cost free-radical polymerization method and analyzed based on Fourier transform infrared spectroscopy and nuclear magnetic resonance. The interactions and structures of the comb copolymers were characterized via X-ray diffraction, differential scanning calorimetry, and thermogravimetric analysis. The comb copolymers showed good solubility in volatile nontoxic ethanol, allowing them to be coated onto microporous polymer supports to form thin-film composite membranes. While both neat POM and PBHP membranes showed very poor separation properties, the POM-PBHP comb copolymers were effective at separating CO 2 from N 2. This is because the POM chains with ether oxygen groups have a strong affinity for CO 2 , leading to high CO 2 permeance, whereas the rigid PBHP chains with aromatic rings hinder N 2 permeance based on reduced chain mobility. All the full-atomistic molecular dynamics simulations based on density functional theory were also used to characterize the molecular structure and binding energy for CO 2 , which is consistent with the experimental results. The performance of the membranes was greatest when the content of PBHP in the copolymer was 15 wt%. The CO 2 /N 2 selectivity and CO 2 permeability reached 46.6 and 111 Barrer, respectively, which represents one of the highest values for alcohol-soluble, additive-free polymeric membranes and is similar to that of commercial PEBAX membrane. Image 103663 • Alcohol-soluble comb copolymers (POM-PBHP) were synthesized. • The POM chains have a strong affinity for CO 2 whereas the rigid PBHP hinder the N 2 permeance. • MD simulations were used to characterize the molecular structure and CO 2 binding energy. • One of the highest performances for alcohol-soluble, additive-free polymer membranes. [ABSTRACT FROM AUTHOR]

Programmed, reshaping hydrogel architectures were fabricated from sugar/hydrogel inks via a three-dimensional printing method involving a stimuli-responsive polymer. We developed a new hydrogel ink composed of monomers (acrylamide [AAm]) and N-isopropylacrylamide [NIPAAm]), and sugar (mixture of glucose and sucrose) as a pore-generator, enabling to improve printability by increasing the ink's viscoelastic properties and induce the formation of macropores in the hydrogel architectures. This study demonstrated that creating macropores in such architectures enables rapid responses to stimuli that can facilitate four-dimensional printing. We printed bilayer structures from monomer inks to which we had added sugar, and we exposed them to processes that cross-linked the monomers and leached out the sugar to create macropores. In comparison with a conventional poly(N-isopropylacrylamide) hydrogel, the macroporous hydrogels prepared using polymerization in the presence of a high concentration of sugar showed higher swelling ratios and exhibited much faster response rates to temperature changes. We used rheometry and scanning electron microscopy to characterize the properties of these inks and hydrogels. The results suggest that this method may provide a readily available route to the rapid design and fabrication of shape-morphing hydrogel architectures with potential application in soft robotics, hydrogel actuators, and tissue engineering. [ABSTRACT FROM AUTHOR]

A synthetic challenge in faceted metal oxide nanocrystals (NCs) is realizing tunable localized surface plasmon resonance (LSPR) near-field response in the infrared (IR). Cube-shaped nanoparticles of noble metals exhibit LSPR spectral tunability limited to visible spectral range. Here, we describe the colloidal synthesis of fluorine, tin codoped indium oxide (F,Sn:In2O3) NC cubes with tunable IR range LSPR for around 10 nm particle sizes. Free carrier concentration is tuned through controlled Sn dopant incorporation, where Sn is an aliovalent n-type dopant in the In2O3 lattice. F shapes the NC morphology into cubes by functioning as a surfactant on the {100} crystallographic facets. Cube shaped F,Sn:In2O3 NCs exhibit narrow, shape-dependent multimodal LSPR due to corner, edge, and face centered modes. Monolayer NC arrays are fabricated through a liquid-air interface assembly, further demonstrating tunable LSPR response as NC film nanocavities that can heighten near-field enhancement (NFE). The tunable F,Sn:In2O3 NC near-field is coupled with PbS quantum dots, via the Purcell effect. The detuning frequency between the nanocavity and exciton is varied, resulting in IR near-field dependent enhanced exciton lifetime decay. LSPR near-field tunability is directly visualized through IR range scanning transmission electron microscopy-electron energy loss spectroscopy (STEM-EELS). STEM-EELS mapping of the spatially confined near-field in the F,Sn:In2O3 NC array interparticle gap demonstrates elevated NFE tunability in the arrays. [ABSTRACT FROM AUTHOR]

[Display omitted] • Base catalyzed depolymerization of lignin was studied in a continuous reactor system at low temperature (≤180 ℃). • Low concentration (<5 %) of alkaline ionic liquid N -allylpyridinium hydroxide ([APy]OH) as a co-solvent in ethylene glycol solution decreased feedstock viscosity and reduced the cost. • [APy]OH as a catalyst also presented a synergistic effect with alkali metal salt (NaCl) and exhibited high aromatics yield. • A hypothetical mechanism was proposed to explain the depolymerization pathway of lignin. A novel alkaline ionic liquids N -allylpyridinium hydroxide ([APy]OH) was successfully designed and developed as a catalyst and co-solvent with ethylene glycol in the continuous depolymerization of lignin. Various reaction conditions, like lignin concentration, water content, and reaction temperature, were investigated under atmospheric pressure. Ethylene glycol was used as main solvent and repolymerization inhibitor of the aldehydes produced. The combination of [APy]OH and alkali metal salts exhibited a good synergistic effect for lignin depolymerization. Then, the depolymerization of three different lignins, including dealkaline lignin (DA-lignin), alkaline lignin (A-lignin), and sodium lignosulfonate (S-lignin), were also studied. S-lignin exhibited the highest yields of total liquid products (21.3 %) and aromatics (10.7 %). The change in lignin structure after depolymerization was observed by means of FT-IR and DTG-DTA techniques. Lastly, a hypothetical pathway for lignin depolymerization was proposed based on the catalytic results of lignin model compounds (LMCs) with different linkages. [ABSTRACT FROM AUTHOR]

Urban climate influences economic activities and the health and safety of urban residents. Therefore, monitoring temperature in urban areas is important. However, owing to the lack of space for an appropriate observation site, an automatic weather station (AWS) was installed on a building rooftop. The rooftop installation can indicate temperature differences depending on the intensity of strong solar radiation and radiant heat of the building, and wind speed. Therefore, in this study, we aimed to provide observation standards for measuring rooftop temperature according to the optimal rooftop material and observation height. Specifically, an AWS was installed on the rooftop of the Gochang Standard Weather Station (GSWO), Jeollabuk-do Province, to observe the urban climate in South Korea and establish suitable weather standards. Different temperatures, optimum surface materials, and optimum heights for measuring the temperature at the rooftop of GSWO were investigated and compared over 1 year. The temperature recorded after installing a palm mat on the rooftop was more similar to that observed in the grassland. Furthermore, the installation height of the temperature sensor of 2.5–3.0 m for the palm mat and 3.5–4.0 m for concrete was found to be the optimal height for observing temperature at the rooftop. [ABSTRACT FROM AUTHOR]

Aiming at enhancing the coke resistance of Ni-based catalysts, the Nd-doped Ni@A 2 O 3 core-shell catalysts were prepared and their catalytic performance was evaluated in the steam reforming of acetic acid (SRAA). The catalysts were characterized by BET, XRD, XRF, HRTEM, H 2 -TPR, NH 3 -TPD, and DTG. The catalytic performance was greatly enhanced by the incorporation of Nd, with decreased yields of CO, CH 4 , and acetone, increased yield of CO 2 , and remarkable carbon resistance. The decoking behavior of the spent catalyst was elucidated by H 2 O18-TSD. A low reaction temperature facilitates the formation of amorphous carbon, leading to catalyst deactivation. The decoking ability of the catalyst is greatly improved by the Nd incorporation but is also catalyzed by the exposed Ni surface. The Ni0.01Nd@Al catalyst greatly balanced the exposed Ni surface and the mobile lattice oxygen, showing the highest catalytic activity, lowest coke deposition, and superb decoking ability. • OSC was introduced to Ni@Al 2 O 3 core-shell catalyst by doping Nd. • Hydrogen yield was enhanced by Nd incorporation with remarkable coke resistance. • Low temperatures induced the formation of amorphous carbon. • Lattice-oxygen-involved surface reactions promoted coke removal and water dissociation. • Both the Ni and lattice oxygen affected the water decoking behavior. [ABSTRACT FROM AUTHOR]

Ribonuclease P (RNase P) complexed with external guide sequence (EGS) represents a nucleic acid-based gene interference approach to knock-down gene expression. Unlike other strategies, such as antisense oligonucleotides, ribozymes, and RNA interference, the RNase P-based technology is unique because a custom-designed EGS molecule can bind to any complementary mRNA sequence and recruit intracellular RNase P for specific degradation of the target mRNA. In this study, we demonstrate that the RNase P-based strategy is effective in blocking gene expression and growth of Kaposi's sarcoma (KS)-associated herpesvirus (KSHV), the causative agent of the leading AIDS-associated neoplasms, such as KS and primary-effusion lymphoma. We constructed 2'-O-methyl-modifiecl EGS molecules that target the mRNA encoding KSHV immediate-early transcription activator Rta, and we administered them directly to human primary-effusion lymphoma cells infected with KSHV. A reduction of 90% in Rta expression and a reduction of &ap;150-fold in viral growth were observed in cells treated with a functional EGS. In contrast a reduction of <10% in the RU expression and viral growth was found in cells that were either not treated with an EGS or that were treated with a disabled EGS containing mutations that preclude recognition by RNase P. Our study provides direct evidence that EGSs are highly effective in inhibiting KSHV gene expression and growth. Exogenous administration of chemically modified EGSs in inducing RNase P-mediated cleavage represent an approach for inhibiting specific gene expression and for treating human diseases, including KSHV- associated tumors. [ABSTRACT FROM AUTHOR]

Surgical methods guided by exogenous fluorescent markers have the potential to define tissue types in real time. Small molecule dyes with efficient and selective renal clearance could enable visualization of the ureter during surgical procedures involving the abdomen and pelvis. These studies report the design and synthesis of a water soluble, net neutral C4′- O -alkyl heptamethine cyanine, Ureter-Label (UL)-766, with excellent properties for ureter visualization. This compound is accessed through a concise synthetic sequence involving an N - to O -transposition reaction that provides other inaccessible C4′- O -alkyl heptamethine cyanines. Unlike molecules containing a C4′- O- aryl substituent, which have also been used for ureter visualization, UL-766 is not reactive towards glutathione and the cellular proteome. In addition, rat models of abdominal surgery reveal that UL-766 undergoes efficient and nearly exclusive renal clearance in vivo . In total, this molecule represents a promising candidate for visualizing the ureter during a variety of surgical interventions. [ABSTRACT FROM AUTHOR]

A 3-year-old dog weighing 8 kg was referred with a disorder of sexual development and persistent urinary incontinence before and after gonadohysterectomy performed at a local animal hospital. Histopathological examination disclosed hypoplasia of the testes, epididymis, pampiniform plexus, and uterus. On ultrasonography, an anomalous structure containing anechoic fluid was identified in the region dorsal to the urinary bladder. An anomalous communication between the proximal urethra and the remnant uterus and vagina was found on retrograde urethrography under fluoroscopy. Reflux of contrast medium into the anomalous structure, suspected to be the uterus and cranial vagina, from the urethra was detected. Computed tomography identified the anomalous structure between the rectum and urethra. The anomalous structure was removed via laparotomy and the urinary incontinence resolved. The diagnosis of XX sex reversal with a developmental anomaly of the genitourinary tract was made on the basis of laparotomy findings and cytogenetic and SRY gene analyses. [ABSTRACT FROM AUTHOR]

Engineered RNase P ribozymes are promising genetargeting agents that can be used in both basic research and clinical applications. We have previously selected ribozyme variants for their activity in cleaving an mRNA substrate from a pool of ribozymes containing randomized sequences. In this study, one of the variants was used to target the mRNA encoding thymidine kinase (TK) of herpes simplex virus 1 (HSV-1). The variant exhibited enhanced cleavage and substrate binding and was at least 30 times more efficient in cleaving TK mRNA in vitro than the ribozyme derived from the wild type sequence. Our results provide the first direct evidence to suggest that a point mutation at nucleotide 95 of RNase P catalytic RNA from Escherichia coli (G95 → U95) increases the rate of cleavage, whereas another mutation at nucleotide 200 (A200 → C200) enhances substrate binding of the ribozyme. A reduction of about 99% in TK expression was observed in cells expressing the variant, whereas a 70% reduction was found in cells expressing the ribozyme derived from the wild type sequence. Thus, the RNase P ribozyme variant is highly effective in inhibiting HSV-1 gene expression. Our study demonstrates that ribozyme variants increase their cleavage activity and efficacy in blocking gene expression in cells through enhanced substrate binding and rate of cleavage. These results also provide insights into the mechanism of how RNase P ribozymes efficiently cleave an mRNA substrate and, furthermore, facilitate the development of highly active RNase P ribozymes for gene-targeting applications. [ABSTRACT FROM AUTHOR]

Ribozymes are promising gene-targeting agents for regulation of gene expression. In our recent studies, RnaseP (M1GS) ribozymes were constructed to target the overlapping region (IE mRNA) of IE1 and IE2 mRNAs of human cytomegalovirus (HCMV) and the mRNA (TK mRNA) coding for thymidine kinase (TK) of herpes simplex virus 1 (HSV-1). Our results indicate that RNase P ribozymes efficiently cleaved the IE mRNA and TK mRNA sequences in vitro. Significant inhibitions (∼75–85%) of HCMV IE1/IE2 and HSV-1 TK expression were observed in cells that expressed these ribozymes while a reduction of less than 10% was found in cells that did not express the ribozymes or expressed a disabled one that contained mutations abolishing catalytic activity. Ribozyme variants, which cleaved a TK mRNA sequence in vitro more efficiently than the ribozyme derived from the wildtype RNase P sequence, were selected by an in vitro selection system. When the selected ribozymes were expressed in cultured cells, they were more effective in inhibiting viral IE1/IE2 and TK expression and viral growth than the wildtype ribozyme sequence. Our results provide the first direct evidence that RNase P ribozymes are highly effective in inhibiting HCMV gene expression and growth. Moreover, a selection system was developed for generating novel ribozyme variants that cleave a mRNA substrate efficiently in vitro. These results suggest that M1GS ribozyme-mediated inhibition of expression of viral genes can be used as a new approach for the studies of HCMV gene function and the treatment of HCMV infection. [Copyright &y& Elsevier]