Estimation of the postmortem duration of mouse tissue by electron spin resonance spectroscopy

Electron spin resonance (ESR) method is a simple method for detecting various free radicals simultaneously and directly. However, ESR spin trap method is unsuited to analyze weak ESR signals in organs because of water-induced dielectric loss (WIDL). To minimize WIDL occurring in biotissues and to improve detection sensitivity to free radicals in tissues, ESR cuvette was modified and used with 5,5-dimethtyl-1-pyrroline N-oxide (DMPO). The tissue samples were mouse brain, hart, lung, liver, kidney, pancreas, muscle, skin, and whole blood, where various ESR spin adduct signals including DMPO-ascorbyl radical (AsA(∗)), DMPO-superoxide anion radical (OOH), and DMPO-hydrogen radical (H) signal were detected. Postmortem changes in DMPO-AsA(∗) and DMPO-OOH were observed in various tissues of mouse. The signal peak of spin adduct was monitored until the 205th day postmortem. DMPO-AsA(∗) in liver (y = 113.8-40.7 log (day), R1 = -0.779, R2 = 0.6, P < .001) was found to linearly decrease with the logarithm of postmortem duration days. Therefore, DMPO-AsA(∗) signal may be suitable for detecting an oxidation stress tracer from tissue in comparison with other spin adduct signal on ESR spin trap method.

Temperature-responsive chromatography for the separation of biomolecules

Temperature-responsive chromatography for the separation of biomolecules utilizing poly(N-isopropylacrylamide) (PNIPAAm) and its copolymer-modified stationary phase is performed with an aqueous mobile phase without using organic solvent. The surface properties and function of the stationary phase are controlled by external temperature changes without changing the mobile-phase composition. This analytical system is based on nonspecific adsorption by the reversible transition of a hydrophilic-hydrophobic PNIPAAm-grafted surface. The driving force for retention is hydrophobic interaction between the solute molecules and the hydrophobized polymer chains on the stationary phase surface. The separation of the biomolecules, such as nucleotides and proteins was achieved by a dual temperature- and pH-responsive chromatography system. The electrostatic and hydrophobic interactions could be modulated simultaneously with the temperature in an aqueous mobile phase, thus the separation system would have potential applications in the separation of biomolecules. Additionally, chromatographic matrices prepared by a surface-initiated atom transfer radical polymerization (ATRP) exhibit a strong interaction with analytes, because the polymerization procedure forms a densely packed polymer, called a polymer brush, on the surfaces. The copolymer brush grafted surfaces prepared by ATRP was an effective tool for separating basic biomolecules by modulating the electrostatic and hydrophobic interactions. Applications of thermally responsive columns for the separations of biomolecules are reviewed here.

[Analysis of metribuzin and its metabolites in livestock products and seafoods by liquid chromatography-tandem mass spectrometry]

A method for simultaneous determination of metribuzin (MET) and three metribuzin metabolites in livestock products and seafoods by liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed. MET and its metabolites were extracted from a sample with acetonitrile, followed by InertSepC18 and BondElut SAX cartridge cleanup. The LC separation was performed on a C18 column using 0.01 mol/L ammonium formate-acetonitrile-methanol (70 :21 : 9) as the mobile phase and MS detection with both positive and negative ion electrospray ionization. The mean recoveries from 10 livestock products and seafoods were generally >60%, and the relative standard deviations were <20%

Hypnotic effects and pharmacokinetics of a single bolus dose of propofol in Japanese macaques (Macaca fuscata fuscata). [corrected]

OBJECTIVE

To describe the hypnotic effects of a single bolus dose of propofol in Japanese macaques, and to develop a pharmacokinetic model.

STUDY DESIGN

Prospective experimental trial.

ANIMALS

Four male macaques (5-6 years old, 8.0-11.2 kg).

METHODS

The macaque was restrained and 8 mg kg(-1) of propofol was administrated intravenously at 6 mg kg(-1) minute(-1) . Behavioural changes without stimuli (first experiment) then responses to external stimuli (the second experiment) were assessed every 2 minutes for 20 minutes. Venous blood samples were collected before and at 1, 5, 15, 30, 60, 120 and 210 minutes after drug administration, and plasma concentrations of propofol were measured (third experiment). Pharmacokinetic modelling was performed using NONMEM VI.

RESULTS

Macaques were recumbent without voluntary movement for a mean 14.0 ± 2.7 SD (range 10.5-16.2) or 10.0 ± 3.4 (7.2-14.5)minutes and recovered to behave as pre-administration by 25.1 ± 3.6 (22.1-30.1) or 22.2 ± 1.5 (21.1-24.3) minutes after the end of propofol administration without or with stimuli, respectively. Respiratory and heart rates were stable throughout the experiments (28-68 breaths minute(-1) and 72-144 beats minute(-1) , respectively). Our final pharmacokinetic model included three compartments and well described the plasma concentration of propofol. The population pharmacokinetic parameters were: V(1)=10.4 L, V(2)=8.38 L, V(3)=72.7 L, CL(1)=0.442 L minute(-1), CL(2)=1.14 L minute(-1), CL(3)= 0.313 L minute(-1), (the volumes of distribution and the clearances for the central, rapid and slow peripheral compartments, respectively).

CONCLUSIONS

Intravenous administration of propofol (8 mg kg(-1)) at 6 mg kg(-1)minute(-1) to Japanese macaques had a hypnotic effect lasting more than 7 minutes. A three-compartment model described propofol plasma concentrations over more than 3 hours.

CLINICAL RELEVANCE

The developed pharmacokinetic parameters may enable simulations of administration protocols to maintain adequate plasma concentration of propofol.

Separation of phosphorylated peptides utilizing dual pH- and temperature-responsive chromatography

The phosphorylation of a peptide is considered to be one of the most important post-translational modification reactions that can alter protein function in mammalian cells. To separate and purify, we developed a dual temperature- and pH-responsive chromatography based on terpolymer composed of N-isopropylacrylamide, N,N'-dimethylaminopropylacrylamide and butylmethacrylate. The property of the surface of the terpolymer-grafted stationary phase altered from hydrophilic to hydrophobic, and from changed to non-charged by changes in the temperature and the pH, respectively. In addition, it was possible to appear and hide ion-exchange groups on the polymer chain surface by temperature changes. These phenomena resulted from changes in the charge and the hydrophobicity of the pH- and temperature-responsive polymer on the stationary surface by controlling the temperature. In the developed environmental-responsive chromatographic system, the ionizable dimethylamino group of N,N'-dimethylaminopropylacrylamide in terpolymer played a key role for the separation. We applied the developed chromatographic system to the separation of phosphorylated compounds, such as phospho-tyrosine, phosphopeptide and oligonucleotides. At a low column temperature, the electrostatic interaction plays a predominant role for retain anionic phosphorylated compounds, because of the strong interaction between the cationic dimethylamino group in the stationary phase and the anionic phosphoric group in the analyte. On the contrary, the hydrophobic interaction became predominant upon increasing the temperature. The results showed that both the electrostatic and the hydrophobic interactions became controllable with a temperature change during the chromatographic process. Dual pH- and temperature-responsive chromatography would be very useful for biomacromolecules separation and purification.

Sialadenoma papilliferum with potentially malignant features

Sialadenoma papilliferum (SP) is a benign non-invasive lesion with slow and limited growth. This report describes an unusual SP that enlarged rapidly and presented as an extensive intraoral tumour highly suspicious for verrucous carcinoma. Radiographic resorption of the underlying bone was evident in the mandible. This type of destructive growth does not conform to any previously reported SP. Histological features were also atypical: surface verrucous hyperplasia and deeper florid cystic-duct adenoma. Overall, the SP is likely to be considered a borderline lesion with malignant potential. Four published cases of malignancy associated with SP showed completely different clinical and pathological settings, further obfuscating the concept of malignant SP.

Thermoresponsive polymer brush surfaces with hydrophobic groups for all-aqueous chromatography

For developing thermoresponsive chromatographic matrices with a strong hydrophobicity, poly(N-isopropylacrylamide-co-n-butyl methacrylate) (poly(IPAAm-co-BMA)) brush grafted silica beads were prepared through a surface-initiated atom transfer radical polymerization (ATRP) with a CuCl/CuCl(2)/Me(6)TREN catalytic system in 2-propanol at 25 degrees C for 16 h. The prepared beads were characterized by chromatographic analysis. Chromatograms of the benzoic-acid family and phenol as model analytes were obtained with high-resolution peaks because of their strong hydrophobic interactions to the densely grafted hydrophobized copolymers on the beads. Retention times of the analytes increased with the increase in BMA composition ratio. Dehydration of grafted copolymer with large BMA composition was performed at low temperature. These results indicated that the copolymer-brush-grafted surface prepared by ATRP was an effective tool for separating hydrophilic analytes at low temperature through modulating the strong hydrophobic interaction.

Increased levels of angiopoietin-2 in induced sputum from smoking asthmatic patients

BACKGROUND

Active cigarette smoking has detrimental effects on asthma morbidity and severity. Angiopoietin-1 has been shown to protect the microvessels against plasma leakage, whereas angiopoietin-2 enhances vascular permeability and subsequently induces airway mucosal oedema. Therefore, it is recently thought that angiopoietin-2 may contribute to the pathophysiology of asthma.

OBJECTIVE

To determine whether angiopoietin-2 levels in the airways are associated with clinical profiles in smoking asthmatics.

METHODS

We measured angiopoietin-1 and -2 levels in induced sputum in 35 normal controls (18 non-smokers and 17 smokers) and 49 asthmatics (24 non-smokers and 25 smokers) before and after inhaled beclomethasone dipropionate (BDP: 800 microg/day) therapy for 12 weeks.

RESULTS

Angiopoietin-1 and -2 levels in induced sputum were significantly higher in asthmatics than in normal controls. Moreover, angiopoietin-2 levels were significantly higher in smoking asthmatics than in non-smoking asthmatics (P=0.0001). The airway vascular permeability index was also higher in smoking asthmatics than in non-smoking asthmatics. Moreover, the angiopoietin-2 level was positively correlated with the airway vascular permeability index (non-smoking asthmatics: r=0.87, P<0.001, smoking asthmatics: r=0.64, P=0.002). After BDP therapy, angiopoietin-1 levels were significantly decreased in non-smoking asthmatics, smoking-cessation asthmatics, and active-smoking asthmatics. In contrast, angiopoietin-2 levels did not differ from before to after BDP therapy in non-smoking asthmatics and active-smoking asthmatics. However, its levels were significantly decreased from before to after BDP therapy in smoking-cessation asthmatics (P=0.002). Although forced expiratory volume in 1 s (FEV(1))/forced vital capacity (FVC) before BDP therapy was comparable in all subgroups, this parameter after BDP therapy was significantly lower in active-smoking asthmatics than in non-smoking and smoking-cessation asthmatics. Moreover, the reduction in angiopoietin-2 levels after BDP therapy in smoking-cessation asthmatics was significantly correlated with an improvement in FEV(1)/FVC.

CONCLUSION

Angiopoietin-2 levels were elevated in the airways of smoking asthmatics, and its levels were associated with impaired airway responses.

Polymeric nanoparticles encapsulating betamethasone phosphate with different release profiles and stealthiness

The purpose of this study was to engineer nanoparticles with various sustained profiles of drug release and prolonged circulation by blending poly(D,L-lactic acid)/poly(D,L-lactic/glycolic acid) (PLA/PLGA) homopolymers and poly(ethylene glycol) (PEG)-block-PLA/PLGA copolymers encapsulating betamethasone disodium 21-phosphate (BP). Nanoparticles of different sizes, drug encapsulation/release profiles, and cellular uptake levels were obtained by mixing homopolymers and block copolymers with different compositions/molecular weights at various blend ratios by an oil-in-water solvent diffusion method. The in vitro release of BP increased with nanoparticles of smaller size or of PLGA homopolymers instead of PLA homopolymers. Furthermore, the uptake of nanoparticles by macrophage-like cells decreased with nanoparticles of higher PEG content, and nanoparticles of PEG-PLGA block copolymers were taken up earlier than those of PEG-PLA block copolymers after incubation with serum. In addition, prolonged blood circulation was observed with nanoparticles of smaller size with higher PEG content, and nanoparticles of PEG-PLA block copolymers remained longer in circulation than those of PEG-PLGA block copolymers. Analysis of BP concentration in organs revealed reduced liver distribution of blended nanoparticles compared with PLA nanoparticles. This is the first study to systematically design and characterize biodegradable PLA/PLGA and PEG-PLA/PLGA-blended nanoparticles encapsulating BP with different release profiles and stealthiness.

Influence of graft interface polarity on hydration/dehydration of grafted thermoresponsive polymer brushes and steroid separation using all-aqueous chromatography

We have prepared poly( N-isopropylacrylamide) (PIPAAm) brush-grafted surfaces with varied temperature-responsive hydrophobic properties through surface-initiated atom transfer radical polymerization (ATRP). These temperature-responsive surfaces were characterized by chromatographic analysis using modified silica beads as a chromatographic stationary phase in aqueous mobile phase. Mixed silane self-assembled monolayers (SAMs) comprising ATRP initiator and silanes with various terminal functional groups were formed on the silica bead surfaces. IPAAm was then polymerized by ATRP using the CuCl/CuCl2/Me6TREN catalyst system in 2-propanol at 25 degrees C for 16 h. The chromatographic retention behavior of steroids on the resulting PIPAAm brushes made on more polar silane components was distinct from that on more apolar silane interfaces. Retention times for steroids on PIPAAm mixed apolar silane graft interfaces were significantly longer than those on analogous polar silane interfaces due to enhanced dehydration of PIPAAm brushes on apolar silane-grafted surfaces. Changes in retention factor, k', on polar silane PIPAAm-grafted interfaces were relatively large compared to that on apolar PIPAAm grafted interfaces due to larger hydration/dehydration alterations of grafted PIPAAm brushes on the former surfaces. Applied step-temperature gradients from 50 to 10 degrees C show that PIPAAm brushes on polar silane interfaces tend to hydrate more, leading to shorter retention times. In conclusion, the polarity of the grafted interface significantly influences the grafted PIPAAm brush hydration/dehydration characteristics and subsequently also the temperature-modulated separation of bioactive compounds in all-aqueous chromatography.

Correlations of health-related quality of life questionnaire results in asthma and allergic rhinitis: effects of a leukotriene receptor antagonist

Bronchial asthma and allergic rhinitis frequently coexist. This study investigated correlations of health-related quality of life (QOL) questionnaires for these diseases, assessing whether the selective leukotriene receptor antagonist (LTRA), pranlukast, had additional benefits to overall asthma control when there was concomitant allergic rhinitis. Patients with asthma-associated allergic rhinitis were randomly allocated to either LTRA(+) (n = 21, treated for 3 months with pranlukast), or LTRA(-) (n = 8, no pranlukast). At study start and at 3 months, pulmonary function was evaluated and QOL assessments were made using the Asthma Health Questionnaire-Japan (AHQ-Japan) and the Japan Rhino-conjunctivitis Quality of Life Questionnaire (JRQLQ). Total scores were significantly correlated both before and after therapy. After 3 months' therapy, pulmonary function and total AHQ-Japan and JRQLQ scores significantly improved in the LTRA(+) group, but not in the LTRA(-) group. A significant correlation between change at 3 months in the AHQ-Japan and JRQLQ scores from baseline values was seen in the LTRA(+) group. LTRA therapy improved allergic rhinitis symptoms, asthma symptoms and pulmonary function.

Preparation of thermoresponsive cationic copolymer brush surfaces and application of the surface to separation of biomolecules

We have prepared poly( N-isopropylacrylamide (IPAAm)- co-2-(dimethylamino)ethylmethacrylate (DMAEMA)) brush-grafted silica bead surfaces through surface-initiated atom transfer radical polymerization (ATRP) using the CuCl/CuCl 2/Me 6TREN catalytic system in 2-propanol at 25 degrees C for 16 h. The prepared temperature-responsive surfaces were characterized by chromatographic analysis using the modified silica beads as stationary phases. Chromatographic retention times for adenosine nucleotides in aqueous mobile phases were significantly increased compared to that previously reported for other cationic hydrogel surfaces, indicating that strong electrostatic cationic copolymer brush interactions occur between the surfaces and nucleotide analytes. Retention times for adenosine nucleotides significantly decreased with increasing column temperature, explained by the decreasing basicity in the copolymer with increasing temperature. Step-temperature gradients from 10 to 50 degrees C shorten ATP retention times. These results indicate that cationic copolymer brush surfaces prepared by ATRP can rapidly alter their electrostatic properties by changing aqueous temperature.