Antibiofilm and antithrombotic hydrogel coating based on superhydrophilic zwitterionic carboxymethyl chitosan for blood-contacting devices

Blood-contacting devices must be designed to minimize the risk of bloodstream-associated infections, thrombosis, and intimal lesions caused by surface friction. However, achieving effective prevention of both bloodstream-associated infections and thrombosis poses a challenge due to the conflicting nature of antibacterial and antithrombotic activities, specifically regarding electrostatic interactions. This study introduced a novel biocompatible hydrogel of sodium alginate and zwitterionic carboxymethyl chitosan (ZW@CMC) with antibacterial and antithrombotic activities for use in catheters. The ZW@CMC hydrogel demonstrates a superhydrophilic surface and good hygroscopic properties, which facilitate the formation of a stable hydration layer with low friction. The zwitterionic-functionalized CMC incorporates an additional negative sulfone group and increased negative charge density in the carboxyl group. This augmentation enhances electrostatic repulsion and facilitates the formation of hydration layer. This leads to exceptional prevention of blood clotting factor adhesion and inhibition of biofilm formation. Subsequently, the ZW@CMC hydrogel exhibited biocompatibility with tests of in vitro cytotoxicity, hemolysis, and catheter friction. Furthermore, in vivo tests of antithrombotic and systemic inflammation models with catheterization indicated that ZW@CMC has significant advantages for practical applications in cardiovascular-related and sepsis treatment. This study opens a new avenue for the development of chitosan-based multifunctional hydrogel for applications in blood-contacting devices.

Antimicrobial and Antifouling Effects of Petal-Like Nanostructure by Evaporation-Induced Self-Assembly for Personal Protective Equipment

Although the personal protective equipment (PPE) used by healthcare workers (HCWs) effectively blocks hazardous substances and pathogens, it does not fully rule out the possibility of infection, as pathogens surviving on the fabric surface pose a substantial risk of cross-infection through unintended means. Therefore, PPE materials that exhibit effective biocidal activity while minimizing contamination by viscous body fluids (e.g., blood and saliva) and pathogen-laden droplets are highly sought. In this study, petal-like nanostructures (PNSs) are synthesized through the vertical rearrangement of colloidal lamellar bilayers via evaporation-induced self-assembly of octadecylamine, silica-alumina sol, and diverse photosensitizer. The developed method is compatible with various fabrics and imparts visible-light-activated antimicrobial and superhydrophobic-based antifouling activities. PNS-coated fabrics could provide a high level of protection and effectively block pathogen transmission as exemplified by their ability to roll off viscous body fluids reducing bacterial droplet adhesion and to inactivate various microorganisms. The combination of antifouling and photobiocidal activities results in the complete inactivation of sprayed pathogen-laden droplets within 30 min. Thus, this study paves the way for effective contagious disease management and the protection of HCWs in general medical environments, inspiring further research on the fabrication of materials that integrate multiple useful functionalities.

Battery-Free, Wireless, Ionic Liquid Sensor Arrays to Monitor Pressure and Temperature of Patients in Bed and Wheelchair

Repositioning is a common guideline for the prevention of pressure injuries of bedridden or wheelchair patients. However, frequent repositioning could deteriorate the quality of patient's life and induce secondary injuries. This paper introduces a method for continuous multi-site monitoring of pressure and temperature distribution from strategically deployed sensor arrays at skin interfaces via battery-free, wireless ionic liquid pressure sensors. The wirelessly delivered power enables stable operation of the ionic liquid pressure sensor, which shows enhanced sensitivity, negligible hysteresis, high linearity and cyclic stability over relevant pressure range. The experimental investigations of the wireless devices, verified by numerical simulation of the key responses, support capabilities for real-time, continuous, long-term monitoring of the pressure and temperature distribution from multiple sensor arrays. Clinical trials on two hemiplegic patients confined on bed or wheelchair integrated with the system demonstrate the feasibility of sensor arrays for a decrease in pressure and temperature distribution under minimal repositioning.

Basic amino acid-mediated cationic amphiphilic surfaces for antimicrobial pH monitoring sensor with wound healing effects

BACKGROUND

The wound healing process is a complex cascade of physiological events, which are vulnerable to both our body status and external factors and whose impairment could lead to chronic wounds or wound healing impediments. Conventional wound healing materials are widely used in clinical management, however, they do not usually prevent wounds from being infected by bacteria or viruses. Therefore, simultaneous wound status monitoring and prevention of microbial infection are required to promote healing in clinical wound management.

METHODS

Basic amino acid-modified surfaces were fabricated in a water-based process via a peptide coupling reaction. Specimens were analyzed and characterized by X-ray photoelectron spectroscopy, Kelvin probe force microscopy, atomic force microscopy, contact angle, and molecular electrostatic potential via Gaussian 09. Antimicrobial and biofilm inhibition tests were conducted on Escherichia coli and Staphylococcus epidermidis. Biocompatibility was determined through cytotoxicity tests on human epithelial keratinocytes and human dermal fibroblasts. Wound healing efficacy was confirmed by mouse wound healing and cell staining tests. Workability of the pH sensor on basic amino acid-modified surfaces was evaluated on normal human skin and Staphylococcus epidermidis suspension, and in vivo conditions.

RESULTS

Basic amino acids (lysine and arginine) have pH-dependent zwitterionic functional groups. The basic amino acid-modified surfaces had antifouling and antimicrobial properties similar to those of cationic antimicrobial peptides because zwitterionic functional groups have intrinsic cationic amphiphilic characteristics. Compared with untreated polyimide and modified anionic acid (leucine), basic amino acid-modified polyimide surfaces displayed excellent bactericidal, antifouling (reduction ~ 99.6%) and biofilm inhibition performance. The basic amino acid-modified polyimide surfaces also exhibited wound healing efficacy and excellent biocompatibility, confirmed by cytotoxicity and ICR mouse wound healing tests. The basic amino acid-modified surface-based pH monitoring sensor was workable (sensitivity 20 mV pH-1) under various pH and bacterial contamination conditions.

CONCLUSION

Here, we developed a biocompatible and pH-monitorable wound healing dressing with antimicrobial activity via basic amino acid-mediated surface modification, creating cationic amphiphilic surfaces. Basic amino acid-modified polyimide is promising for monitoring wounds, protecting them from microbial infection, and promoting their healing. Our findings are expected to contribute to wound management and could be expanded to various wearable healthcare devices for clinical, biomedical, and healthcare applications.

Transparent, Robust, and Photochemical Antibacterial Surface Based on Hydrogen Bonding between a Si-Al and Cationic Dye

Healthcare-associated infections can occur and spread through direct contact with contaminated fomites in a hospital, such as mobile phones, tablets, computer keyboards, doorknobs, and other surfaces. Herein, this study shows a transparent, robust, and visible light-activated antibacterial surface based on hydrogen bonds between a transparent silica-alumina (Si-Al) sol-gel and a visible light-activated photosensitizer, such as crystal violet (CV). The study of the bonding mechanisms revealed that hydrogen bonding predominantly occurs between the N of CV and Al-OH. Apart from CV, Si-Al can be combined with a variety of dyes, highlighting its potential for wide application. The Si-Al@CV film selectively generates singlet oxygen using ambient visible light, triggering potent photochemical antibacterial performance against Gram-positive and Gram-negative bacteria. Additionally, the Si-Al@CV film is stable even after mechanical stability tests such as tape adhesion, scratch, bending, and water immersion. In vitro cytotoxicity tests using C2C12 myoblast cells showed that the Si-Al@CV film is a biocompatible material. This work suggests a new approach for designing a transparent and robust touchscreen surface with photochemical antibacterial capability against healthcare-associated infections.

Photobiocidal-triboelectric nanolayer coating of photosensitizer/silica-alumina for reusable and visible-light-driven antibacterial/antiviral air filters

Outbreaks of airborne pathogens pose a major threat to public health. Here we present a single-step nanocoating process to endow commercial face mask filters with photobiocidal activity, triboelectric filtration capability, and washability. These functions were successfully achieved with a composite nanolayer of silica-alumina (Si-Al) sol-gel, crystal violet (CV) photosensitizer, and hydrophobic electronegative molecules of 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane (PFOTES). The transparent Si-Al matrix strongly immobilized the photosensitizer molecules while dispersing them spatially, thus suppressing self-quenching. During nanolayer formation, PFOTES was anisotropically rearranged on the Si-Al matrix, promoting moisture resistance and triboelectric charging of the Si-Al/PFOTES-CV (SAPC)-coated filter. The SAPC nanolayer stabilized the photoexcited state of the photosensitizer and promoted redox reaction. Compared to pure-photosensitizer-coated filters, the SAPC filter showed substantially higher photobiocidal efficiency (∼99.99 % for bacteria and a virus) and photodurability (∼83 % reduction in bactericidal efficiency for the pure-photosensitizer filter but ∼0.34 % for the SAPC filter after 72 h of light irradiation). Moreover, after five washes with detergent, the SAPC filter maintained its photobiocidal and filtration performance, proving its reusability potential. Therefore, this SAPC nanolayer coating provides a practical strategy for manufacturing an antimicrobial and reusable mask filter for use during the ongoing COVID-19 pandemic.

Mini-laser based submicron aerosol generator for the simple and stable simulation of combustion particulate matter

Air pollution causes millions of deaths every year. The aerosols, especially airborne nanoparticles generated by combustion, have detrimental effect on health. To protect public health against harmful aerosols, efforts to develop effective air cleaning technology have continued over the past several decades. However, the aerosol generation method used in air cleaning performance tests still rely largely on the traditional methods such as burning cigarettes, paper, and incense. Since the traditional method is inaccurate and unsteady, a more precisely controlled aerosol generation method should be developed. Here, we present a simple and inexpensive aerosol generation method that can easily and consistently produce submicron aerosols through laser ablation. This device constitutes an integrated system with a high-quality mini laser for rapid aerosol generation and a two-axis moving stage for continuous aerosol generation. We demonstrate that the concentration of generated aerosols could be easily controlled by selecting the laser irradiation time and power, resulting in the generation of ~10⁴ particles/cm³ within a few seconds. In addition, the shape and size of generated aerosols can be controlled by changing the target material. This submicron aerosol generation process can be stably maintained for up to 1 h using small-sized (3 cm × 8 cm) affordable and accessible materials, such as wood and leather, highlighting the advantages of this inexpensive and easy-to-use combustion airborne submicron particle generation method.

Amino acid-mediated negatively charged surface improve antifouling and tribological characteristics for medical applications

To prevent infections associated with biomedical catheters, various antimicrobial coatings have been investigated. However, those materials do not provide consistent antibacterial effects or biocompatibility, generally, due to degradation of the coating materials, in vivo. Additionally, biomedical catheters must have low surface friction to reduce tribological damage. In this study, we developed an antifouling surface composed of biocompatible amino acids (leucine, taurine, and aspartic acid) on polyimide, via modification using a series of facile immersion steps with waterborne reactions. The naturally derived amino acid could be formed highly biostable amide bonds on the polyimide surface like peptides. The amino acid-modified surface formed a water layer with antifouling performance through the hydrophilic properties of amino acids. Amino acid-mediated modification reduced adhesion up to 84.45% and 94.81% against Escherichia coli and Staphylococcus epidermidis, respectively, and exhibited an excellent prevention to adhesion against the proteins, albumin and fibrinogen. Evaluation of the surface friction of the catheter revealed a dramatic reduction in the tribological force after amino acid modification on polyimide that of 0.81 N to aspartic acid of 0.44 N. These results clearly demonstrate a reduced occurrence of infections, thrombi and tribological damage following the relatively facile surface modification of catheters. The proposed modification method can be used in a continuous manufacturing process via using the same time of modification steps for the easy producing the product. Moreover, the method uses biocompatible naturally derived materials and can be applied to medical equipment that requires biocompatibility and biofunctionality with polyimide surfaces.

Battery-free, wireless soft sensors for continuous multi-site measurements of pressure and temperature from patients at risk for pressure injuries

Capabilities for continuous monitoring of pressures and temperatures at critical skin interfaces can help to guide care strategies that minimize the potential for pressure injuries in hospitalized patients or in individuals confined to the bed. This paper introduces a soft, skin-mountable class of sensor system for this purpose. The design includes a pressure-responsive element based on membrane deflection and a battery-free, wireless mode of operation capable of multi-site measurements at strategic locations across the body. Such devices yield continuous, simultaneous readings of pressure and temperature in a sequential readout scheme from a pair of primary antennas mounted under the bedding and connected to a wireless reader and a multiplexer located at the bedside. Experimental evaluation of the sensor and the complete system includes benchtop measurements and numerical simulations of the key features. Clinical trials involving two hemiplegic patients and a tetraplegic patient demonstrate the feasibility, functionality and long-term stability of this technology in operating hospital settings.

Water-Repellent TiO2-Organic Dye-Based Air Filters for Efficient Visible-Light-Activated Photochemical Inactivation against Bioaerosols

Recently, bioaerosols, including the 2019 novel coronavirus, pose a serious threat to global public health. Herein, we introduce a visible-light-activated (VLA) antimicrobial air filter functionalized with titanium dioxide (TiO₂)-crystal violet (CV) nanocomposites facilitating abandoned visible light from sunlight or indoor lights. The TiO₂-CV based VLA antimicrobial air filters exhibit a potent inactivation rate of ∼99.98% and filtration efficiency of ∼99.9% against various bioaerosols. Under visible-light, the CV is involved in overall inactivation by inducing reactive oxygen species production both directly (CV itself) and indirectly (in combination with TiO₂). Moreover, the susceptibility of the CV to humidity was significantly improved by forming a hydrophobic molecular layer on the TiO₂ surface, highlighting its potential applicability in real environments such as exhaled or humid air. We believe this work can open a new avenue for designing and realizing practical antimicrobial technology using ubiquitous visible-light energy against the threat of infectious bioaerosols.

Influences of Absorbed Dose Rate on the Mechanical Properties and Fiber-Matrix Interaction of High-Density Polyethylene-Based Carbon Fiber Reinforced Thermoplastic Irradiated by Electron-Beam

In this study, a high-density polyethylene (HDPE)-based carbon fiber-reinforced thermoplastic (CFRTP) was irradiated by an electron-beam. To assess the absorbed dose rate influence on its mechanical properties, the beam energy and absorbed dose were fixed, while the absorbed dose rates were varied. The tensile strength (TS) and Young's modulus (YM) were evaluated. The irradiated CFRTP TS increased at absorbed dose rates of up to 6.8 kGy/s and decreased at higher rates. YM showed no meaningful differences. For CFRTPs constituents, the carbon fiber (CF) TS gradually increased, while the HDPE TS decreased slightly as the absorbed dose rates increased. The OH intermolecular bond was strongly developed in irradiated CFRTP at low absorbed dose rates and gradually declined when increasing those rates. X-ray photoelectron spectroscopy analysis revealed that the oxygen content of irradiated CFRTPs decreased with increasing absorbed dose rate due to the shorter irradiation time at higher dose rates. In conclusion, from the TS viewpoint, opposite effects occurred when increasing the absorbed dose rate: a favorable increase in CF TS and adverse decline of attractive hydrogen bonding interactions between HDPE and CF for CFRTPs TS. Therefore, the irradiated CFRTP TS was maximized at an optimum absorbed dose rate of 6.8 kGy/s.

Selective multi-nanosoldering for fabrication of advanced solution-processed micro/nanoscale metal grid structures

Solution-processed metal grid transparent conductors with low sheet resistance, high optical transmittance and good mechanical flexibility have great potential for use in flexible optoelectronic devices. However, there are still remaining challenges to improve optoelectrical properties and electromechanical stability of the metallic structures due to random loose packings of nanoparticles and the existence of many pores. Here we introduce a selective multi-nanosoldering method to generate robust metallic layers on the thin metal grid structures (< a thickness of 200 nm), which are generated via self-pining assisted direct inking of silver ions. The selective multi-nanosoldering leads to lowering the sheet resistance of the metal grid transparent conductors, while keeping the optical transmittance constant. Also, it reinforces the electromechanical stability of flexible metal grid transparent conductors against a small bending radius or a repeated loading. Finally, organic light-emitting diodes based on the flexible metal grid transparent conductors are demonstrated. Our approach can open a new route to enhance the functionality of metallic structures fabricated using a variety of solution-processed metal patterning methods for next-generation optoelectronic and micro/nanoelectronic applications.

Washable antimicrobial polyester/aluminum air filter with a high capture efficiency and low pressure drop

Here, we introduce a reusable bifunctional polyester/aluminum (PET/Al) air filter for the high efficiency simultaneous capture and inactivation of airborne microorganisms. Both bacteria of Escherichia coli and Staphylococcus epidermidis were collected on the PET/Al filter with a high efficiency rate (∼99.99%) via the electrostatic interactions between the charged bacteria and fibers without sacrificing pressure drop. The PET/Al filter experienced a pressure drop approximately 10 times lower per thickness compared with a commercial high-efficiency particulate air filter. As the Al nanograins grew on the fibers, the antimicrobial activity against airborne E. coli and S. epidermidis improved to ∼94.8% and ∼96.9%, respectively, due to the reinforced hydrophobicity and surface roughness of the filter. Moreover, the capture and antimicrobial performances were stably maintained during a cyclic washing test of the PET/Al filter, indicative of its reusability. The PET/Al filter shows great potential for use in energy-efficient bioaerosol control systems suitable for indoor environments.

Roll-to-roll processed, highly conductive, and flexible aluminum (Al) electrodes based on Al precursor inks

R2R machine is designed for the Al thin film coating to the flexible substrate, and the substrate can be applied to the flexible electronics.

Al-Coated Conductive Fibrous Filter with Low Pressure Drop for Efficient Electrostatic Capture of Ultrafine Particulate Pollutants

Here, we demonstrate a new strategy of air filtration based on an Al-coated conductive fibrous filter for high efficient nanoparticulate removals. The conductive fibrous filter was fabricated by a direct decomposition of Al precursor ink, AlH₃{O(C₄H₉)₂}, onto surfaces of a polyester air filter via a cost-effective and scalable solution-dipping process. The prepared conductive filters showed a low sheet resistance (<1.0 Ω sq^-1), robust mechanical durability and high oxidative stability. By electrostatic force between the charged fibers and particles, the ultrafine particles of 30-400 nm in size were captured with a removal efficiency of ∼99.99%. Moreover, the conductive filters exhibited excellent performances in terms of the pressure drop (∼4.9 Pa at 10 cm s^-1), quality factor (∼2.2 Pa^-1 at 10 cm s^-1), and dust holding capacity (12.5 μg mm^-2). After being cleaned by water, the filtration efficiency and pressure drop of the conductive filter was perfectly recovered, which indicates its good recyclability. It is expected that these promising features make the conductive fibrous filter have a great potential for use in low-cost and energy-efficient air cleaning devices as well as other relevant research areas.

Highly Stretchable, Hysteresis-Free Ionic Liquid-Based Strain Sensor for Precise Human Motion Monitoring

A highly stretchable, low-cost strain sensor was successfully prepared using an extremely cost-effective ionic liquid of ethylene glycol/sodium chloride. The hysteresis performance of the ionic-liquid-based sensor was able to be improved by introducing a wavy-shaped fluidic channel diminishing the hysteresis by the viscoelastic relaxation of elastomers. From the simulations on visco-hyperelastic behavior of the elastomeric channel, we demonstrated that the wavy structure can offer lower energy dissipation compared to a flat structure under a given deformation. The resistance response of the ionic-liquid-based wavy (ILBW) sensor was fairly deterministic with no hysteresis, and it was well-matched to the theoretically estimated curves. The ILBW sensors exhibited a low degree of hysteresis (0.15% at 250%), low overshoot (1.7% at 150% strain), and outstanding durability (3000 cycles at 300% strain). The ILBW sensor has excellent potential for use in precise and quantitative strain detections in various areas, such as human motion monitoring, healthcare, virtual reality, and smart clothes.

In situ ruminal degradation characteristics of dry matter and crude protein from dried corn, high-protein corn, and wheat distillers grains

Background

The continuing growth of the ethanol industry has generated large amounts of various distillers grains co-products. These are characterized by a wide variation in chemical composition and ruminal degradability. Therefore, their precise formulation in the ruminant diet requires the systematic evaluation of their degradation profiles in the rumen.

Methods

Three distillers grains plus soluble co-products (DDGS) namely, corn DDGS, high-protein corn DDGS (HP-DDGS), and wheat DDGS, were subjected to an in situ trial to determine the degradation kinetics of the dry matter (DM) and crude protein (CP). Soybean meal (SBM), a feed with highly degradable protein in the rumen, was included as the fourth feed. The four feeds were incubated in duplicate at each time point in the rumen of three ruminally cannulated Hanwoo cattle for 1, 2, 4, 6, 8, 12, 24, and 48 h.

Results

Wheat DDGS had the highest filterable and soluble A fraction of its DM (37.2 %), but the lowest degradable B (49.5 %; P < 0.001) and an undegradable C fraction (13.3 %; P < 0.001). The filterable and soluble A fraction of CP was greatest with wheat DDGS, intermediate with corn DDGS, and lowest with HP-DDGS and SBM; however, the undegradable C fraction of CP was the greatest with HP-DDGS (41.2 %), intermediate with corn DDGS (2.7 %), and lowest with wheat DDGS and SMB (average 4.3 %). The degradation rate of degradable B fraction (% h⁻¹) was ranked from highest to lowest as follows for 1) DM: SBM (13.3), wheat DDGS (9.1), and corn DDGS and HP-DDGS (average 5.2); 2) CP: SBM (17.6), wheat DDGS (11.6), and corn DDGS and HP-DDGS (average 4.4). The in situ effective degradability of CP, assuming a passage rate of 0.06 h⁻¹, was the highest (P < 0.001) for SBM (73.9 %) and wheat DDGS (71.2 %), intermediate for corn DDGS (42.5 %), and the lowest for HP-DDGS (28.6 %), which suggests that corn DDGS and HP-DDGS are a good source of undegraded intake protein for ruminants.

Conclusions

This study provided a comparative estimate of ruminal DM and CP degradation characteristics for three DDGS co-products and SBM, which might be useful for their inclusion in the diet according to the ruminally undegraded to degraded intake protein ratio.

High-Performance, Solution-Processed, Embedded Multiscale Metallic Transparent Conductors

High-performance multiscale metallic transparent conductors (TCs) are demonstrated by incorporating Ag nanowire (NW) networks into microscale Ag grid structures. Highly conductive Ag grids are fabricated via direct imprinting of an Ag ion ink using a reservoir-assisted mold. In this mold, a macroscale cavity, called the "reservoir", is designed to connect to a grid-patterned cavity. The reservoir has a large cavity volume, which reduces unwanted residual layers within the grid spacings by introducing a thinner liquid film. The reservoir undergoes a large volume reduction during mold deformation, which improves ink filling within the grid-patterned cavity through deformation-induced ink injection. The multiscale metallic TCs show a sheet resistance (Rs) of <1.5 Ω/sq and a transmittance (T) of 86% at 550 nm, superior to the corresponding values of Ag NW networks (Rs of 15.6 Ω/sq at a similar T). We estimate the Rs-T performances of the Ag grids using geometrical calculations and demonstrate that their integration can enhance the opto-electrical properties of the Ag NW networks. Multiscale metallic TCs are successfully transferred and embedded into a transparent, flexible, and UV-curable polymer matrix. The embedded multiscale metallic TCs show reasonable electromechanical and chemical stability. The utility of these TCs is demonstrated by fabricating flexible organic solar cells.

Effect of feeding a by-product feed-based silage on nutrients intake, apparent digestibility, and nitrogen balance in sheep

BACKGROUND

Literature is lacking on the effects of feeding by-product feed (BF)-based silage on rumen fermentation parameters, nutrient digestion and nitrogen (N) retention in sheep. Therefore, this study was conducted to determine the effect of replacing rye straw with BF-based silage as a roughage source on ruminal parameters, total-tract apparent nutrient digestibility, and N balance in sheep.

METHODS

The by-product feed silage was composed of spent mushroom substrate (SMS) (45 %), recycled poultry bedding (RPB) (21 %), rye straw (11 %), rice bran (10.8 %), corn taffy residue (10 %), protected fat (1.0 %), bentonite (0.6 %), and mixed microbial additive (0.6 %). Six sheep were assigned randomly to either the control (concentrate mix + rye straw) or a treatment diet (concentrate mix + BF-based silage).

RESULTS

Compared with the control diet, feeding a BF-based silage diet resulted in similar ruminal characteristics (pH, acetate, propionate, and butyrate concentrations, and acetate: propionate ratio), higher (p < 0.05) ruminal NH3-N, higher (p < 0.05) ether extract digestibility, similar crude protein digestibility, lower (p < 0.05) dry matter, fiber, and crude ash digestibilities, and higher (p < 0.05) N retention (g/d).

CONCLUSION

The BF-based silage showed similar energy value, higher protein metabolism and utilization, and lower fiber digestion in sheep compared to the control diet containing rye straw.

Effect of Feeding a Mixed Microbial Culture Fortified with Trace Minerals on the Performance and Carcass Characteristics of Late-fattening Hanwoo Steers: A Field Study

This study was conducted to determine the effects of feeding a trace minerals-fortified microbial culture (TMC) on the performance and carcass characteristics of late-fattening Hanwoo steers. A mixture of microbes (0.6% [v/w] of Enterobacter sp., Bacillus sp., Lactobacillus sp., and Saccharomyces sp.) was cultured with 99% feedstuff for ensiling and 0.4% trace minerals (zinc, selenium, copper, and cobalt). Sixteen late-fattening steers (mean age, 21.8 months) were allocated to two diets: a control diet (concentrate mix and rice straw) and a treated diet (control diet+3.3% TMC). At a mean age of 31.1 months, all the steers were slaughtered. The addition of TMC to the diet did not affect the average daily weight gain of the late fattening steers, compared with that of control steers. Moreover, consuming the TMC-supplemented diet did not affect cold carcass weight, yield traits such as back fat thickness, longissimus muscle area, yield index or yield grade, or quality traits such as meat color, fat color, texture, maturity, marbling score, or quality grade. However, consumption of a TMC-supplemented diet increased the concentrations of zinc, selenium, and sulfur (p<0.05) in the longissimus muscle. With respect to amino acids, animals consuming TMC showed increased (p<0.05) concentrations of lysine, leucine, and valine among essential amino acids and a decreased (p<0.05) concentration of proline among non-essential amino acids. In conclusion, the consumption of a TMC-supplemented diet during the late-fattening period elevated the concentrations of certain trace minerals and essential amino acids in the longissimus muscle, without any deleterious effects on performance and other carcass characteristics of Hanwoo steers.

Cup-to-disc and arteriole-to-venule ratios in preterm birth

AIMS

To investigate the influence of preterm birth on the optic disc and retinal vessels by measurements of cup-to-disc (C/D) ratio and arteriole-to-venule (A/V) ratio.

METHODS

Eighty-three eyes of 42 preterm births were included. In the age- and sex-matched control group, 83 eyes of 42 full-term births were used. Fundus color photographs were taken. ImageJ software was used to calculate C/D and A/V ratios from the fundus images.

RESULTS

Fundus photographs were taken at 8.01 ± 2.22 years of age for the preterm group and 8.01 ± 2.13 years of age for the control group. The mean gestational age of the preterm group was 27(4)/7 weeks (range, 24-34 weeks). The preterm group had significantly larger C/D ratio and smaller A/V ratio (mean ± standard deviation: 0.46 ± 0.12 and 0.59 ± 0.08, respectively) than the control group (0.36 ± 0.07 and 0.68 ± 0.07, respectively) after spherical equivalent refractive error was adjusted.

CONCLUSIONS

Preterm birth is significantly associated with larger C/D ratio and smaller A/V ratio. These findings show the effect of preterm birth on the development of optic disc and retinal vessel development.

The ossification pattern in paediatric occipito-cervical spine: is it possible to estimate real age?

AIM

To retrospectively analyse the synchondrosis from the occipital bone to the whole cervical spine and determine the feasibility and validity of age estimation using computed tomography (CT) images.

MATERIAL AND METHODS

A total of 231 cervical spine or neck CT images of young children (<7 years of age) were examined. Twelve ossification centres were assessed (occiput: n = 2; atlas: n = 2; axis, n = 6; whole sub-axial vertebra: n = 2), and the ossification process was graded as open (O, fully lucent), osseous bridging (B, partially ossified), and fusion (F, totally ossified). After the first analysis was completed, the resulting chronological chart was used to estimate the age of 10 new cases in order to confirm the usefulness of the chart.

RESULTS

Infancy was easily estimated using the sub-axial or C2 posterior ossification centres, while the posterior occipital regions provided good estimation of age between 1-2 years. The most difficult period for accurate age estimation was between 2-4 years. However, the C2 anterior (neurocentral ossification) and C1 posterior regions did yield information to help determine the age around 3 years. The anterior occipital region was useful for age estimation between 4-5 years, and the C1-anterior region was potentially useful to help decide among the other parameters. The test for age estimation (TAE) had a very high ICC score (0.973) among the three observers.

CONCLUSION

Segmentalised analysis can enhance the ability to estimate real age, at least by the year. The analysis of the occipital bone made a strong contribution to the usefulness of the chorological chart. An organised chronological chart can provide readily available information for age estimation, and the primary application of the above data (TAE) demonstrated the validity of this approach.

Effect of By-product Feed-based Silage Feeding on the Performance, Blood Metabolites, and Carcass Characteristics of Hanwoo Steers (a Field Study)

This study was conducted to determine the effects of feeding by-product feed (BF)-based silage on the performance, blood metabolite parameters, and carcass characteristics of Hanwoo steers. The BF-based silage was composed of 50% spent mushroom substrate, 21% recycled poultry bedding, 15% cut ryegrass straw, 10.8% rice bran, 2% molasses, 0.6% bentonite, and 0.6% microbial additive (on a wet basis), and ensiled for over 5 d. Fifteen steers were allocated to three diets during the growing and fattening periods (3.1 and 9.8 months, respectively): a control diet (concentrate mix and free access to rice straw), a 50% BF-based silage diet (control diet+50% of maximum BF-based silage intake), and a 100% BF-based silage diet (the same amount of concentrate mix and ad libitum BF-based silage). The BF-based silage was fed during the growing and fattening periods, and was replaced with larger particles of rice straw during the finishing period. After 19.6 months of the whole period all the steers were slaughtered. Compared with feeding rice straw, feeding BF-based silage tended (p = 0.10) to increase the average daily gain (27%) and feed efficiency (18%) of the growing steers, caused by increased voluntary feed intake. Feeding BF-based silage had little effect on serum constituents, electrolytes, enzymes, or the blood cell profiles of fattening steers, except for low serum Ca and high blood urea concentrations (p<0.05). Feeding BF-based silage did not affect cold carcass weight, yield traits such as back fat thickness, longissimus muscle area, yield index or yield grade, or quality traits such as meat color, fat color, texture, maturity, marbling score, or quality grade. However, it improved good quality grade (1⁺ and 1⁺⁺) appearance rates (60% for the control group vs 100% for the BF-based silage-fed groups). In conclusion, cheap BF-based silage could be successfully used as a good quality roughage source for beef cattle.

Annealing-free, flexible silver nanowire-polymer composite electrodes via a continuous two-step spray-coating method

For the realization of high-efficiency flexible optoelectronic devices, transparent electrodes should be fabricated through a low-temperature process and have the crucial feature of low surface roughness. In this paper, we demonstrated a two-step spray-coating method for producing large-scale, smooth and flexible silver nanowire (AgNW)-poly3,4-ethylenedioxythiophene:polystyrenesulfonate (PEDOT:PSS) composite electrodes. Without the high-temperature annealing process, the conductivity of the composite film was improved via the lamination of highly conductive PEDOT:PSS modified by dimethyl sulfoxide (DMSO). Under the room temperature process condition, we fabricated the AgNW-PEDOT:PSS composite film showing an 84.3% mean optical transmittance with a 10.76 Ω sq(-1) sheet resistance. The figure of merit Φ(TC) was higher than that obtained from the indium tin oxide (ITO) films. The sheet resistance of the composite film slightly increased less than 5.3% during 200 cycles of tensile and compression folding, displaying good electromechanical flexibility for use in flexible optoelectronic applications.

Effect of lysine to digestible energy ratio on growth performance and carcass characteristics in finishing pigs

This experiment was performed to investigate the effects of lysine (Lys) to DE ratio on growth performance, and carcass characterics in finishing barrows. Ninety six cross-bred finishing barrows ((Landrace×Yorkshire) ×Duroc, average BW 58.25±0.48 kg) were assigned as a randomized complete block design by 2 energy levels and 4 Lys:DE ratios on the basis of BW to one of 8 treatments with 3 replications with 4 animals per pen. The levels of DE and Lys:DE ratio for each treatment were i) DE 3.35 Mcal/kg, 1.5 g Lys/Mcal DE, ii) DE 3.35 Mcal/kg, 1.8 g Lys/Mcal DE, iii) DE 3.35 Mcal/kg, 2.1 g Lys/Mcal DE, iv) DE 3.35 Mcal/kg, 2.4 g Lys/Mcal DE, v) DE 3.60 Mcal/kg, 1.5 g Lys/Mcal DE, vi) DE 3.60 Mcal/kg, 1.8 g Lys/Mcal DE, vii) DE 3.60 Mcal/kg, 2.1 g Lys/Mcal DE, viii) DE 3.60 Mcal/kg, 2.4 g Lys/Mcal DE. During finishing period from 58 kg to 103 kg of BW, increased energy density in the diet increased (p<0.05) ADG and gain:feed ratio, but did not influence ADFI. As Lys:DE ratio was increased, ADG, ADFI and gain:feed ratio were improved in finishing barrows (p<0.05). There were positive interactions (p<0.05) between carcass weight, grade, and backfat thickness and energy density and Lys level (p<0.05). In conclusion, data from our current study suggest that maximum yields including ADG, gain:feed ratio, carcass weight and grade can be achieved by administrating finishing pigs with an ideal Lys:DE ratio, Lys 2.1 g/DE Mcal.

Novel growth and properties of GaAs nanowires on Si substrates

Straight, vertically aligned GaAs nanowires were grown on Si(111) substrates coated with thin GaAs buffer layers. We find that the V/III precursor ratio and growth temperature are crucial factors influencing the morphology and quality of buffer layers. A double layer structure, consisting of a thin initial layer grown at low V/III ratio and low temperature followed by a layer grown at high V/III ratio and high temperature, is crucial for achieving straight, vertically aligned GaAs nanowires on Si(111) substrates. An in situ annealing step at high temperature after buffer layer growth improves the surface and structural properties of the buffer layer, which further improves the morphology of the GaAs nanowire growth. Through such optimizations we show that vertically aligned GaAs nanowires can be fabricated on Si(111) substrates and achieve the same structural and optical properties as GaAs nanowires grown directly on GaAs(111)B substrates.

Scopolamine-induced deficits in social memory in mice: reversal by donepezil

Deficits in social behaviour is a characteristic of numerous mental disorders including autism, schizophrenia, depression and Alzheimer's disease. For the assessment of pharmacological and genetic experimental disease models, conventional social interaction tasks bear the uncertainty that any drug-induced abnormality of the investigator may feed back to the drug-free companion modifying its reactions. A considerable technical improvement was recently reported by Moy et al. [Moy SS, Nadler JJ, Perez A, Barbaro RP, Johns JM, Magnuson T, et al. Sociability and preference for social novelty in five inbred strains: an approach to assess autistic-like behaviours in mice. Genes Brain Behav 2004;3:287-302] in which the drug free partner is confined to a small cage and social contacts of the investigator are recorded uncontaminated of any social reactions of the stranger. Using this novel behavioural paradigm, we here show in C57Bl/6 female mice that sociability (social interaction with a stranger mouse) is not impaired after administration of the anxiolytic diazepam (0.1-1 mg/kg) or the muscarinic antagonist scopolamine hydrobromide (0.1-1 mg/kg). However, social memory tested after a short time interval was impaired by both drugs in a dose-dependent manner (diazepam: > or = 0.5mg/kg; scopolamine: > or = 0.3mg/kg). The scopolamine-induced short-term memory deficit was reversed to normal by the choline esterase inhibitor donepezil (1 mg/kg). Given this dependence of social recognition on the cholinergic system, combined with the clinical observation of reduced social contacts in dementia patients, sociability may offer a novel endpoint biomarker with translational value in experimental models of cognitive dysfunction.

beta-lapachone induces growth inhibition and apoptosis in bladder cancer cells by modulation of Bcl-2 family and activation of caspases

AIM

To study in vitro the molecular mechanism of apoptosis caused by beta-lapachone, a quinone obtained from the bark of the lapacho tree (Tabebuia avellanedae).

MATERIALS AND METHODS

The study was carried out on human bladder carcinoma T24 cell line. Determination of cell viability was done using trypan blue exclusion method, apoptosis quantitative estimation - by DAPI staining and agarose gel electrophoresis for DNA fragmentation. Flow cytometry analysis, RT-PCR and Western blot analysis, colorimetric assay of caspase activity were applied as well.

RESULTS

It was found that in micromolar range of concentrations beta-lapachone inhibited the viability of T24 cells by inducing apoptosis, which could be proved by formation of apoptotic bodies and DNA fragmentation. Treatment of T24 cells with beta-lapachone resulted in a down-regulation of Bcl-2 expression and up-regulation of Bax expression. beta-lapachone-induced apoptosis was also associated with activation of caspase-3 and caspase-9, inhibition of IAP expression, and degradation of poly (ADP-ribose) polymerase, phospholipase C-gamma1 and beta-catenin proteins. At the same time Fas and FasL levels were inhibited upon treatment with beta-lapachone in a concentration-dependent manner.

CONCLUSION

beta-lapachone-induced apoptosis in T24 cells is mediated, at least in part, by the mitochondrial-signaling pathway.

Antinociceptive effects of bee venom acupuncture (apipuncture) in rodent animal models: a comparative study of acupoint versus non-acupoint stimulation

From a clinical perspective, the alternative forms of acupoint stimulation including electroacupuncture, moxibustion and acupressure appear to have more potent analgesic effects than manual needle acupuncture. Bee venom (BV) injection has also been reported to produce persistent nociceptive stimulation and to cause neuronal activation in the spinal cord. In previous study, we observed that BV stimulation into acupoint, namely BV acupuncture or Apipuncture, produced more potent anti-inflammatory and antinociceptive potency in rodent arthritis model as comparing with that of non-acupoint injection. Based on previous report, we decided to further investigate that BV injection into an acupoint produces antinociception as a result of its potent chemical stimulatory effect in both abdominal stretch assay and formalin test. Different doses of BV were injected into an acupoint or a non-acupoint 30 min prior to intraplantar formalin injection or intraperitoneal acetic acid injection. Using the abdominal stretch assay, we found that the high dose of BV (1:100 diluted in 20microl saline) produced a potent antinociceptive effect irrespective of the site of BV injection. In contrast the antinociceptive effect observed in both the writhing and formalin tests following administration of a low dose of BV (1:1000 diluted in 20microl saline) was significantly different between acupoint and non-acupoint sites. BV injection into an acupoint (Zhongwan, Cv. 12) was found to produce significantly greater antinociception than non-acupoint injection (10 mm from Zhongwan, Cv. 12) in the abdominal stretch assay. Similarly, in the formalin test, acupoint (Zusanli, St. 36) injection of BV produced more potent antinociception than non-acupoint injection (gluteal muscle). In contrast, BV injection into an arbitrary non-acupoint site on the back did not produce antinociception in either the writhing or formalin test. These results indicate that BV injection directly into an acupoint can produce a potent antinociceptive effect and suggest that this alternative form of acupoint stimulation (Apipuncture) may be a promising method for the relief of pain.

Sustained signaling by phospholipase C-gamma mediates nerve growth factor-triggered gene expression

In contrast to conventional signaling by growth factors that requires their continual presence, a 1-min pulse of nerve growth factor (NGF) is sufficient to induce electrical excitability in PC12 cells due to induction of the peripheral nerve type 1 (PN1) sodium channel gene. We have investigated the mechanism for this triggered signaling pathway by NGF in PC12 cells. Mutation of TrkA at key autophosphorylation sites indicates an essential role for the phospholipase C-gamma (PLC-gamma) binding site, but not the Shc binding site, for NGF-triggered induction of PN1. In concordance with results with Trk mutants, drug-mediated inhibition of PLC-gamma activity also blocks PN1 induction by NGF. Examination of the kinetics of TrkA autophosphorylation indicates that triggered signaling does not result from sustained activation and autophosphorylation of the TrkA receptor kinase, whose phosphorylation state declines rapidly after NGF removal. Rather, TrkA triggers an unexpectedly prolonged phosphorylation and activation of PLC-gamma signaling that is sustained for up to 2 h. Prevention of the elevation of intracellular Ca2+ levels using BAPTA-AM results in a block of PN1 induction by NGF. Sustained signaling by PLC-gamma provides a means for differential neuronal gene induction after transient exposure to NGF.

Fibroblast growth factor receptor 3 induces gene expression primarily through Ras-independent signal transduction pathways

Fibroblast growth factor receptors (FGFR) are widely expressed in many tissues and cell types, and the temporal expression of these receptors and their ligands play important roles in the control of development. There are four FGFR family members, FGFR-1-4, and understanding the ability of these receptors to transduce signals is central to understanding how they function in controlling differentiation and development. We have utilized signal transduction by FGF-1 in PC12 cells to compare the ability of FGFR-1 and FGFR-3 to elicit the neuronal phenotype. In PC12 cells FGFR-1 is much more potent in the induction of neurite outgrowth than FGFR-3. This correlated with the ability of FGFR-1 to induce robust and sustained activation of the Ras-dependent mitogen-activated protein kinase pathways. In contrast, FGFR-3 could not induce strong sustained Ras-dependent signals. In this study, we analyzed the ability of FGFR-3 to induce the expression of sodium channels, peripherin, and Thy-1 in PC12 cells because all three of these proteins are known to be induced via Ras-independent pathways. We determined that FGFR-3 was capable of inducing several Ras-independent gene expression pathways important to the neuronal phenotype to a level equivalent of that induced by FGFR-1. Thus, FGFR-3 elicits phenotypic changes primarily though activation of Ras-independent pathways in the absence of robust Ras-dependent signals.

The effects of N-methyl-N-nitrosourea and azoxymethane on focal cerebral infarction and the expression of p53, p21 proteins

If the activity of pro-apoptotic genes can be down-regulated by certain chemicals, cells may be protected from apoptosis. To test this hypothesis in a cerebral infarction model, we used N-methyl-N-nitrosourea (MNU) and azoxymethane (AOM), which were approved gene-modulating chemicals. A focal cerebral infarction was created by coagulation of the right middle cerebral artery and ipsilateral common carotid artery (CCA) and simultaneous transient occlusion of the contralateral CCA for 30 min in 25 adult Sprague-Dawley rats that were sacrificed 24 h later. In one group (n=7), MNU (5 mg/kg) was injected intravenously 30 min before initiation of ischemia. In another group (n=7), AOM (15 mg/kg) was administered intraperitoneally before 24 h of ischemia. The infarction volumes were checked and the brains were stained for p53 and p21 proteins. The width in micrometers of the peri-infarct area containing p53 or p21 protein-positive cells, and the number of p53 or p21 protein-positive cells (cells/HPF) were measured at an adjacent peri-infarct area. The AOM-treated group showed a significantly reduced infarction volume (by 42.5%, p<0.001), a significantly greater number of p53 positive cells (by 12.0%, p<0. 05), and a significantly wider p53 protein-positive area (by 15.6%, p<0.01) than the untreated group. AOM did not show any influence on the expression pattern of the p21 protein. MNU had no effect in the expression of p53 or p21 proteins. As a result, we concluded that AOM revealed a protective effect in ischemia by suppressing the pro-apoptotic activity of the p53 gene. Safer chemicals that can modulate apoptotic genes, if any, will provide a new therapeutic modality for cerebral infarction.

Distinction among neuronal subtypes of voltage-activated sodium channels by mu-conotoxin PIIIA

The functional properties of most sodium channels are too similar to permit identification of specific sodium channel types underlying macroscopic current. Such discrimination would be particularly advantageous in the nervous system in which different sodium channel family isoforms are coexpressed in the same cell. To test whether members of the mu-conotoxin family can discriminate among known neuronal sodium channel types, we examined six toxins for their ability to block different types of heterologously expressed sodium channels. PIIIA mu-conotoxin blocked rat brain type II/IIA (rBII/IIA) and skeletal muscle sodium current at concentrations that resulted in only slight inhibition of rat peripheral nerve (rPN1) sodium current. Recordings from variant lines of PC12 cells, which selectively express either rBII/IIA or rPN1 channel subtypes, verified that the differential block by PIIIA also applied to native sodium current. The sensitivity to block by PIIIA toxin was then used to discriminate between rBII/IIA and rPN1 sodium currents in NGF-treated PC12 cells in which both mRNAs are induced. During the first 24 hr of NGF-treatment, PN1 sodium channels accounted for over 90% of the sodium current. However, over the ensuing 48 hr period, a sharp rise in the proportion of rBII/IIA sodium current occurred, confirming the idea, based on previous mRNA measurements, that two distinct sodium channel types appear sequentially during neuronal differentiation of PC12 cells.

Protection of methamphetamine nigrostriatal toxicity by dietary selenium

Multiple dose administration of methamphetamine (MA) results in long-lasting toxic effects in the nigrostriatal dopaminergic system. These effects are considered to be primarily due to oxidative damage mediated by increased production of hydrogen peroxide or other reactive oxygen species in the dopaminergic system. The present study was designed to determine the protective effects of dietary antioxidant selenium on MA-induced neurotoxicity in the nigrostriatal dopaminergic system. Male C57BL/6J mice were fed either selenium-deficient (< 0.01 ppm Se) or selenium-replete (0.2 ppm Se) diets for 90 days. MA treatment decreased the dopamine (DA) levels in the striatum and substantia nigra (SN) of both Se-replete and Se-deficient animals. However, in Se-replete animals, this DA depletion was significantly attenuated in both the striatum and SN. A novel observation is that MA administration resulted in increased activity of Cu,Zn-SOD in the brains of both Se-deficient and Se-replete animals. However, MA administration to Se-deficient animals exhibited a higher Cu,Zn-SOD activity in the nigrostriatal system than the control animals. Elevated malondialdehyde (MDA) levels in the striatum and SN were also observed in Se-deficient MA-treated animals. Se repletion significantly increased the glutathione peroxidase (GPx) activity and the ratio of reduced glutathione (GSH)/oxidized glutathione (GSSG) in the MA-treated animals. In conclusion, we have shown that dietary Se attenuated methamphetamine neurotoxicity and that this protection involves GPx-mediated antioxidant mechanisms. Even though Cu,Zn-SOD activity was significantly elevated by MA treatment, the role of this enzyme in MA-mediated neurotoxicity is not yet clear.

Use of public mental health services by Russian refugees

OBJECTIVES

This study identifies the demographic characteristics and patterns of mental health service use among Russian refugees in New York State.

METHODS

Data from a 1995 statewide survey of characteristics of patients served by the New York State mental health system were analyzed using chi square statistics and logistic regression.

RESULTS

The demographic characteristics and service-use patterns of Russian refugees are different from those of non-Russian refugees and non-refugees. Russian refugees who used mental health services were likely to be older women with major depression who were enrolled in Medicaid and who were using those services for the first time. Relying heavily on themselves, family members, or friends as referral sources, they tended to use exclusively individual, outpatient services at voluntary, nonprofit agencies.

CONCLUSIONS

Existing services systems must recognize the presence of Russian refugees. To improve access and service use, outreach efforts to the refugee community should be conducted, and services must be tailored to meet their mental health needs.

Immune-stimulating properties of polysaccharides from Phellodendri cortex (Hwangbek)

Heteropolysaccarides were isolated from the Korean medicinal plant, Phellodendri cortex (Hwangbek), by hot water and alkali extractions. The extracted polysaccharides were fractionated into eight fractions and they are mainly composed of D-N-acetylglucosamine, D-galactose, D-mannose, and D-glucose. Among the polysaccharide fractions, Fr.-2 showed a potent B-lymphocyte-stimulating activity in a system using polyclonal antibody forming cells in C57BL/6XC3H mice at dosages of 2-10 mg. On the basis of their solubility in aqueous ethanol, four fractions of Fr.-2-1 to Fr.-2-4 were further obtained from the Fr.-2, and Fr.-2-3 was divided into Fr.-2-3-1, 2, 3, and 4 by DEAE cellulose chromatography. The main activity was found in Fr.-2-3-2, which contained 100% (w/w) of carbohydrates and further purified to Fr.-2-3-2-2 by gel filtration chromatography using TSK Gel HW50S. Fr.-2-3-2-2, having a molecular weight of about 230 kDa, showed the highest B-cell-stimulating activity and the half-maximal concentration for B-lymphocyte-stimulating activity was ca. 2.2 microg/ml.

Aspalatone, a new antiplatelet agent, attenuates the neurotoxicity induced by kainic acid in the rat

The antioxidant efficacy of aspalatone (APT; acetyl salicylic acid maltol ester), a new antiplatelet agent, has been characterized in vivo as well as in vitro, and several observations indicated that the antioxidant could prevent the neuroexcitation caused by oxidative stress. In this report, the effect of APT was evaluated on kainic acid (KA)-induced neurotoxicity, since the neurotoxicity induced by KA is, at least in part, mediated via the formation of free radicals. The results showed that pretreatments with APT or maltol (MAL) significantly attenuated seizure activity, oxidative stress (lipid peroxidation and protein oxidation) and the loss of hippocampal neurons induced by KA. On the other hand, the pretreatments with aspirin (ASP), ASP together with MAL or vitamin E failed to protect against the toxicity produced by KA suggesting that the mechanism of action for APT on the KA-induced neurotoxicity is different from that of ASP. These finding raise the possibility that salicylmaltol, a metabolite of APT, plays a role in preventing the neurotoxicity evoked by KA. Therefore, our results suggest that an APT-related antioxidant mechanism, which is linked to the MAL moiety, is involved in the neuroprotective effect against KA.

Nitric oxide is a regulator of bone remodelling

Nitric oxide (NO) is known to be implicated in the metabolism of bone, especially as a mediator of cytokine effects on the remodelling of bone tissue. In this study we examine whether NO affects the osteoblast activation or the osteoclast differentiation of primary mouse osteoblast-like and osteosarcoma ROS 17/2.8 cell lines. Primary osteoblast and ROS 17/2.8 cells released NO upon stimulation of interleukin-1 beta, tumour necrosis factor-alpha, and interferon-gamma. Sodium nitroprusside, a donor of nitric oxide, increased the activity of alkaline phosphatase in ROS 17/2.8 cells as well as the number of calcified nodule formations in primary mouse osteoblast-like cells. Sodium nitroprusside also completely inhibited 1 alpha, 25-(OH)2D3-induced osteoclast generation in a high concentration (100 microM). However, a low concentration of sodium nitroprusside (3-30 microM) significantly increased the generation of osteoclasts. These results indicated that NO appears to be an important regulatory molecule in the processes of bone formation and resorption. Hence, NO may be involved in the pathogenesis of bone loss in diseases associated with cytokine activation, such as periodontal disease and rheumatoid arthritis.

Effect of a novel saponin adjuvant derived from Quillaja saponaria on the immune response to recombinant hepatitis B surface antigen

Adjuvant activity of saponins extracted from the South American tree Quillaja saponaria has been demonstrated with many antigens. Recently, four saponin fractions (designated as QS-7, QS-17, QS-18, and QS-21) with adjuvant activity were purified by reverse phase chromatography. In particular, efficacy of the less toxic QS-21 fraction has been demonstrated with several recombinant viral antigens including HIV gp120. Here, we report a novel saponin fraction (designated as QS-L1) derived from Quillaja saponaria. Unlike previously identified saponins, QS-L1 had a different chemical structure and showed adjuvant activity only when administered in the presence of alum-precipitated antigen. Interestingly, the QS-L1 greatly increased not only a humoral immune response but also cellular immune response to recombinant hepatitis B virus surface antigen (HBsAg). Furthermore, QS-L1 showed lower toxicity in vivo and in vitro than the previously identified saponin fraction, QS-21. Finally, we examined the chemical structure of the QS-L1 using mass spectroscopic analysis, carbohydrate composition analysis and NMR spectroscopic analysis. Thus, our results indicated that this novel QS-L1 saponin fraction had several desirable properties required for an effective adjuvant.

A new antithrombotic agent, aspalatone, attenuated cardiotoxicity induced by doxorubicin in the mouse; possible involvement of antioxidant mechanism

A new antithrombotic agent, aspalatone (APT; acetyl salicylic acid maltol ester), was synthesized by esterification of acetyl salicylic acid (ASP) and maltol (MAL). It was suggested that APT possessed an antioxidant effect in in vitro. To evaluate the putative antioxidant effect of APT in in vivo, we developed doxorubicin (DOX)-related cardiac damage, which might be implicated by oxidative stress. Vitamin E (Vit E) was included in the present study as an example of an antioxidant. Prolonged treatments with APT, MAL and Vit E significantly reduced the mortality in animals receiving multiple dose of DOX (3 mg/kg x 4). The potential role of APT, MAL and Vit E against DOX insult may be explained by the induction of glutathione peroxidase activity accompanied by the inhibition of lipid peroxidation. Prolonged treatments of APT, MAL and Vit E also ablated histopathological evidence of DOX cardiomyopathy. ASP challenge, however, did not affect the mortality, myocardial lesion and antioxidant deficit induced by DOX treatments. In conclusion, the protective effect of APT was equipotent to that of Vit E against DOX cardiotoxicity. The results also suggest that the antiperoxidative effect of APT plays a protective role in DOX-related cardiotoxic side effect.

Experimentally induced Chiari-like malformation with myeloschisis in chick embryos

Though several pathogenetic theories concerning the frequent association of Chiari malformation and hydrocephalus with myeloschisis have been suggested, none of them explains all the aspects of the disorder. To investigate whether myeloschisis is the direct cause of Chiari malformation and hydrocephalus or these conditions are the results of another basic event, we observed the morphological changes of the posterior cranial fossa and its components in the chick embryos with surgically induced myeloschisis. To make myeloschistic lesions, we opened the neural tube for a length of 9-11 somites in Hamburger and Hamilton stage 16-19 chick embryos. They were divided into cervicothoracic (C-T) and lumbosacral(L-S) groups according to the area of incision. The embryos were re-incubated until postoperative day 11. In the control group, embryos were incubated with the eggshell window open as their experimental counterparts. The survival rates of each group were as follows; 11% (9 survivors/85 operated embryos), 8% (7/83), and 17% (10/60) in the C-T, L-S and control groups, respectively. Myeloschisis positive rates were 100% in the operated groups and 0% in the control group. The heads of embryos were sectioned along the sagittal plane to observe the morphological changes in the posterior cranial fossa and its components. Of the survivors, five in the C-T group, two in the L-S group and six in the control group were available for light microscopic inspection. In the majority of embryos with myeloschisis, without difference between the C-T and L-S groups, the fourth ventricles were smaller than those of the control group and the subarachnoid spaces in the posterior cranial fossa were also narrower. In embryos with severe changes, the cerebellum displaced downward comparing with that of the control embryos. No evidence of hydrocephalus was present Though not always typical, morphological changes similar to Chiari malformation were observed in chick embryos with surgically induced myeloschisis. It suggests a strong direct causal relationship between the two conditions and supports the theories of derangements in cerebrospinal fluid dynamics rather than those of primary mesenchymal or neural origin as a pathogenetic mechanism of Chiari malformation.

Persistent organochlorine residues in northern fur seal from the Pacific coast of Japan since 1971

The present study was conducted to determine the residue levels of persistent organochlorines such as PCB homologues, DDT and its metabolites, and HCH isomers in the ventral blubber of female northern fur seal (Callorhinus ursinus) collected off Sanriku, the Pacific coast of northern Japan, since 1971. Among the organochlorines examined, the concentrations of PCBs and DDTs were found to be high in all samples. The residue levels of these two contaminants showed a drastic reduction following maturity and then a slight increase after the retirement from pregnancy/menopause. Temporal variation of PCB and DDT residues showed maximum levels around 1976 and then decreased, whereas HCH residue levels revealed a very slow declining pattern. Considering the concentrations and compositions of the residues, the northern fur seal is likely to be exposed to organochlorine contamination deriving from global terms. In this context, continuous contamination has been foreseen with regard to PCB and HCH residues. The pattern of organochlorine residues indicated that the northern fur seal has higher metabolic capacity than Dall's porpoise, while it is comparable to those of larga seal and Steller sea lion.

Epidemiologic study of hepatitis B in pregnant Korean women

The positive rates of hepatitis B viral markers according to many epidemiologic factors were analyzed in 2,873 pregnant women who delivered at St. Columban’s Hospital in Mokpo City from April 1st, 1985 to March 31st, 1986.

The following results were obtained: The overall HBsAg positivity in all pregnant women was 8.3%. The positive rate of HBsAg was unrelated to age. It was 13.2% in the 11–20 year age group. 12.5% in the 31–40 year age group, 7.8% in the 21–30 year age group and 0.0% in the 41–50 year age group. The positive rate of HBsAg was slightly related to locality. It was a little higher in women who grew up in rural areas (8.6%) than in urban areas (7.7%). The positive rate of HBsAg was unrelated to educational background. The positive rate of HBsAg was unrelated to economic status. It was 8.7% in the highest income group and 8.6% in the lowest income group. The positive rate of HBsAg was higher in cases who had injections more than four times. The positive rate of HBsAg was higher, but not significantly, in cases who had received blood transfusion. The positive rate of HBsAg was higher, but not significantly, in cases who had more than three siblings (0.05

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Rectal hemorrhage from ulcerated appendiceal stump nine years after appendectomy. Report of a case

Significant lower gastrointestinal hemorrhage from an ulcerated appendiceal stump after remote uncomplicated appendectomy is reported. The diagnosis was established by pathologic examination of the surgical specimen, but the area of bleeding was localized by preoperative colonoscopy. Angiography or isotope scan might also have identified the site of more rapid bleeding.