Calibration methods for microdialysis sampling in vivo: muscle and adipose tissue

Calibration methods for microdialysis sampling were studied in the muscle and adipose tissue of rats. Both the delivery method and the no-net-flux method were used to determine the extraction efficiency (EE) of acetaminophen and caffeine in both tissues. There was no concentration dependence of the EE either in vitro or in vivo for either acetaminophen or caffeine. The EEs determined by the delivery and no-net-flux methods were not different. However, the EEs of both caffeine and acetaminophen determined in vitro were significantly higher than those determined in the muscle and adipose. This indicates that mass transfer in the tissue is the rate-determining factor for the EE in vivo. The relative difference between the EE in vitro and the EE in the muscle was smaller than the difference between the EE in vitro and the EE in the adipose. In addition, the EE in the muscle decreased more than the EE in the adipose after the animal was euthanized. This indicated that exchange between the extracellular fluid and plasma is the rate-determining step in mass transport relative to microdialysis sampling. This has a more significant effect on the EE in the muscle than the EE in the adipose. Both the delivery and no-net-flux methods can be used to calibrate microdialysis probes in the muscle and adipose.     

Histological study of some Echium vulgare, Pulmonaria officinalis and Symphytum officinale populations

Plants living in different ecological habitats can show significant variability in their histological and phytochemical characters. The main histological features of various populations of three medicinal plants from the Boraginaceae family were studied. Stems, petioles and leaves were investigated by light microscopy in vertical and transverse sections. The outline of the epidermal cells, as well as the shape and cell number of trichomes was studied in leaf surface casts. Differences were measured among the populations of Echium vulgare in the width and height of epidermis cells in the stem, petiole and leaf, as well as in the size of palisade cells in the leaves. Among the populations of Pulmonaria officinalis significant differences were found in the length of trichomes and in the slightly or strongly wavy outline of epidermal radial cell walls. Populations of Symphytum officinale showed variance in the height of epidermal cells in leaves and stems, length of palisade cells and number of intercellular spaces in leaves, and the size of the central cavity in the stem. Boraginaceae bristles were found to be longer in plants in windy/shady habitats as opposed to sunny habitats, both in the leaves and stems ofP. officinalis and S. officinale, which might be connected to varying levels of exposure to wind. Longer epidermal cells were detected in the leaves and stems of both E. vulgare and S. officinale plants living in shady habitats, compared with shorter cells in sunny habitats. Leaf mesophyll cells were shorter in shady habitats as opposed to longer cells in sunny habitats, both in E. vulgare and S. officinale. This combination of histological characters may contribute to the plant's adaptation to various amounts of sunshine. The reported data prove the polymorphism of the studied taxa, as well as their ability to adapt to various ecological circumstances.     

Variability of total flavonoid, polyphenol and tannin contents in some Lythrum salicaria populations

Lythrum salicaria L. can vary in some morphological and phytochemical features according to its habitat. The present study investigates and compares the total flavonoid, polyphenol and tannin composition of twelve populations of L. salicaria collected from different ecological habitats in south-west Hungary. We studied the plant heights and soil moistures of the habitats analyzing the potential correlation between the morphological and environmental factors and chemical compositions. Total flavonoid, polyphenol and tannin contents were determined according to the valid spectroscopic methods of the European Pharmacopoeia. Total flavonoid content was higher in the populations collected during the main blooming period in August than at the beginning of flowering in July. Higher values for total polyphenol and tannin were detected in flowering branch tips in August than in July, and higher ones in leaves and shoots in July than in August. The highest flavonoid content was measured in the leaves, followed by the flowering branches and shoots as opposed to the total polyphenol and tannin contents, which were higher in the flowering branch tips than in the other organs.     

Crystal structure transformations in ammonium and alkali metal perchlorates

A comparative study of the polymorphic transformations in ammonium and the alkali metal perchlorates has been made using differential thermal analysis. Certain correlations have been attempted between the observed trends in the transformation temperatures and available crystallographic and thermodynamic data. The transformation in the case of sodium perchlorate shows pronounced second-order effects. Considerable hysteresis is observed in the transformations in ammonium, potassium, rubidium and caesium perchlorates. Doping of ammonium perchlorate with ammonium phosphate is seen to result in an upward shift in the transformation temperature and an increase in the thermal hysteresis. Prior mechanical and thermal treatment is also seen to result in a broadening of the hysteresis loops in the case of ammonium and potassium perchlorates. The results are explained in terms of contrapolarization effects and the production of strain in the material as a result of prior treatment.     

Biological Characterization of Ingredients in OPLC-BioArena-Greenhouse-System: Unique Reactions of Endogenous HCHO and O3 in In Vitro and In Vivo Conditions

In the case of two “old medicines”, the extension of the results from the in vitro BioArena studies was successfully solved for in vivo (greenhouse) conditions. These preliminary results of in vitro and in vivo studies confirmed the unique role and function of HCHO and O₃ in the antibiotic effect of these two chemical substances, and in the basal and induced resistance. In the future, for the characterization of known and new active substances, in vitro and in vivo biological studies will be recommended in addition to chemical and physical characterization.

     

Localisation and accumulation of a new carotenoporphyrin in two primary tumour models

We have investigated the tumour-localising properties and in vivo fluorescence kinetics of a hexamethoxylated carotenqporphyrin (CP6) in two primary tumour models: UV-B-induced early skin cancer in hairless mice and chemically induced mucosal dysplasia in the rat palate. CP6 fluorescence kinetics are investigated by measuring in vivo fluorescence spectra and images of the mouse skin and the rat palate at different time points after injection. For the tumour-localising properties, microscopic phase-contrast and fluorescence images are recorded. The in vivo fluorescence kinetics in the mouse skin show localization of CP6 in the tumours. However, fluorescence microscopy images show that CP6 localises in the dermis and structures that are not related to the malignant transformation of the mouse skin. The fluorescence kinetics in the rat palate show a significant correlation between the degree of malignancy and the CP6 fluorescence build-up time in the palate. The microscopic images show that CP6 fluorescence localises in the connective tissue and not in the dysplastic epithelium. In conclusion, CP6 does not localise preferentially in (pre-) cancerous tissue in the two primary tumour models studied here, in contrast to reports about localisation of carotenoporphyrins in transplanted tumours. However, the CP6 build-up time in rat palates correlates with the degree of malignancy and this might possibly be a useful parameter in tumour detection.     

Radiochemistry teaching and research activities in Brazil

Summary Much concern has been expressed lately about the decline of teaching and research activities in radiochemistry in many countries, as was discussed in an IAEA Technical Meeting in Antalya, Turkey, in 2002, and also at MTAA-11 in Guildford, UK. In the IAEA meeting, a survey was presented about the current situation in different regions of the world (Eastern Europe, East and West Asia, Africa, North America and Latin America) by experts of each region. In the case of Brazil, which has nuclear research reactors and also cyclotrons in operation, the teaching and research activities in radiochemistry are concentrated in the three main institutes of the Brazilian Nuclear Energy Commission, in the University of S?o Paulo and in other universities, in different regions of the country. In the present paper, a closer look is given to the radiochemistry teaching and research activities that are being conducted nowadays in Brazil, comprising: number of radiochemistry courses and students being formed, main research areas being conducted, as well as research and production of radioisotopes for nuclear medicine, using nuclear reactors and cyclotrons.     

Interactions and reactions of monolayers and Langmuir-Blodgett multilayers with compounds in the bulk phase

Studies performed on the interactions and reactions of compounds in the bidimensional state, essentially in monolayers and Langmuir-Blodgett multilayers, with substances in the aqueous subphase are reported. More precisely, the following is illustrated: (i) interactions between acid amphiphiles and prevalently bivalent ions placed in the aqueous support and between compounds capable of functioning like ion carriers in monolayers and ions in the subphase, in order to build mimetic membranes capable of selective ion transport; and the complexation of amphiphiles in monolayer with ions in the bulk liquid phase, in order to build chemical sensors to ions; (ii) the reactions of photoinduced electron transfer between a partner in mono- or multimolecular films and a partner in the subphase, which may determine the fundamental parameters and the differences with the same reactions in the bulk phase; and (iii) the reactions of enzymatic hydrolysis between the monolayer of a glyceride, which constitutes the reaction support, and the enzyme in the liquid bulk phase, which constitutes the subphase. The mechanism of the reactions and its inhibition are clarified. To conclude, possible future developments connected with the areas studied are examined.     

黄鸣龙——我国有机化学的一位先驱

黄鸣龙院士(1898-1979)1919年浙江医药专科学校毕业,1924年德国柏林大学有机药物化学博士;1924-1934年任浙江医专教授、主任,卫生署化学部主任;1934-1940年在欧洲先灵公司等从事研究工作;1940年回国在昆明任中研院化学所研究员,兼任西南联大教授;1945年赴美在哈佛大学,默克公司从事研究工作。1952年绕道欧洲回国,先后在中国人民解放军医学科学院化学系和中国科学院上海有机化学研究所任研究员。1955年当选为中国科学院学部委员(院士)。黄先生一生从事有机化学的教育和研究工作,他在有机化学的“结构与机理”以及“反应和合成”二大方面都作出了在国内外具有深远影响的工作。20世纪40年代黄先生发现了变质山道年4个立体异构体的循环转变,堪称立体化学的经典之作;1948年发表了黄鸣龙还原反应;1952年归国后引领和发展了我国的甾体化学研究,带领了我国甾体药物的生产发展,是我国甾体药物工业的奠基人。黄先生治学严谨,既重视应用研究,又强调基础研究;关注学习新知识、新概念,又更重视实验技术。黄先生教书育人,身体力行,是我国有机化学发展的先驱者和奠基人。     

Riboflavin and UV-Light Based Pathogen Reduction: Extent and Consequence of DNA Damage at the Molecular Level

We are developing a technology based on the combined application of riboflavin (RB) and light for inactivating pathogens in blood products while retaining the biological functions of the treated cells and proteins. Virus and bacteria reduction measured by tissue culture infectivity or colony formation with UV light alone and in combination with RB yield equivalent results. The effects of RB as a sensitizing agent on DNA in white cells, bacteria and viruses in combination with UV light exposure have been evaluated. UV-mediated DNA degradation in Jurkat T cells and leukocytes in plasma as measured by the FlowTACS assay was significantly increased in the presence of RB. Agarose gel electrophoretic analysis of DNA in Escherichia coli and leukocytes in plasma demonstrated enhanced DNA degradation in the presence of RB. UV light in combination with RB prevented the reactivation of lambda phage compared with samples irradiated in the absence of RB. UV-mediated oxidative damage in calf thymus DNA was also enhanced in the presence of RB. These observations clearly demonstrate that the presence of RB and UV light selectively enhances damage to the guanine bases in DNA. These data also suggest that the type and extent of damage to DNA for virus in the presence of RB and light make it less likely to be repaired by normal repair pathways available in host cells.     

Dendrimers with electroactive units in the core or in each branching centre

Interest in dendrimers is mostly focused on their capability of performing specific functions which, in their turn, derive from the possibility of incorporating in predetermined sites of the structure selected functional groups (‘pieces of information’). From a topological viewpoint we can distinguish dendrimers containing electroactive units (a) in the core, (b) in the branches, (c) in the surface, (d) in the core and in the branches, (e) in the core and in the surface, (f) in the branches and in the surface, and (g) in the core, branches and surface. In this article we review the behaviour of dendrimers with electroactive units buried in the core and dendrimers with electroactive units in each branching centre investigated in our laboratory. To cite this article: M. Venturi, P. Ceroni, C. R. Chimie 6 (2003).     

Protolytic dissociation of cyanophenols in ground and excited states in alcohol and water solutions

The effect of cyano substituents on acidity in ground and excited states of mono- and dicyanophenols was investigated. The equilibrium dissociation constants of 3,4-dicyanophenol in ground and lowest excited states in water solution and the change of these constants in the excited state during the transfer to the ground state for o-, m-, p-cyanophenol and 3,4-dicyanophenol in alcohol and water solutions were determined. It was shown that the cyano substitution increases the acidity of ortho-, meta- and dicyano-derivative in ground state in comparison to the phenol, which makes the anions of these derivatives appear in solutions from methanol to 1-butanol. In the excited state the acidity of investigated compounds changes significantly in comparison to the ground state. 3,4-Dicyanophenol is the strongest acid in the lowest excited singlet state, while p-cyanophenol is the weakest one in both alcohol and water solutions. The distribution of the electronic charge and dipole moments of all investigated cyanophenols in ground and excited states were determined on the basis of ab initio calculations using the GAMESS program.     

Über die Herkunft der Lactatdehydrogenase und anderer Zellenzyme im normalen Blutserum

The origin of cell enzymes in normal blood serum is as yet unexplained. In a comparative study in man, marmoset monkey, rat and mouse we have investigated which of 10 major organs could be excluded as significant sources of LDH in normal serum. LDH-1, LDH-2 and LDH-3 are the strongest isoenzyme fractions in serum of man and marmoset. Based on the LDH isoenzyme patterns liver and skeleton muscle were excluded in man; liver, skeleton muscle, spleen, large intestine and leucocytes were excluded in the marmoset. LDH-5 is the predominat isoenzyme in the serum of the rat and of the mouse. Heart and kidney were excluded as LDH sources in the rat; heart, kidney and lung were excluded in the mouse. One must assume that the mechanism of cell enzyme release into the blood is identical in all species. Hence, if an organ is excluded as source of LDH in one species it is also to be excluded in all other species. Erythrocytes and thrombocytes were recognized as the sources of LDH in normal serum of the four species. Species differences of the LDH isoenzyme patterns in these organs are reflected in comparable differences of the isoenzyme patterns in serum. The major portion of LDH in normal serum is released during the physiological turnover of these cells. This hypothesis includes all enzymes which are present in erythrocytes and thrombocytes. Only few organ specific enzymes which are present in normal serum, originate from other tissues.     

Simultaneous liquid chromatographic determination of 39 polycyclic aromatic hydrocarbons in indoor and outdoor air and application to a survey on indoor air pollution in Fuji, Japan

An analytical method was established for the simultaneous determination of 39 polycyclic aromatic hydrocarbons (PAHs) in air. The method was applied to a survey of gaseous and particulate PAHs in household indoor air. The survey was performed in 21 houses in the summer of 1999 and in 20 houses in the winter of 1999-2000 in Fuji, Japan. Thirty-eight PAHs were determined in indoor and outdoor air in the summer, and 39 PAHs were determined in indoor and outdoor air in the winter. The concentrations of gaseous PAHs in indoor air tended to be higher than those in outdoor air in the summer and winter. The concentrations of particulate PAHs in indoor air were the same as or lower than those in outdoor air in the summer and winter. PAH profiles, correlations between PAH concentrations, and multiple regression analysis were used to determine the factors affecting the indoor PAH concentrations. These results showed that gaseous PAHs in indoor air were primarily from indoor emission sources, especially during the summer, and that indoor particulate PAH concentrations were significantly influenced by outdoor air pollution.     

Surfactant charge effects on the location, vibrational spectra, and relaxation dynamics of cyanoferrates in reverse micelles

Ultrafast infrared spectroscopy has been used to measure vibrational energy relaxation (VER) and reorientation (Tr) times for the high frequency CN stretches of potassium ferrocyanide and ferricyanide and the NO stretch of sodium nitroprusside (SNP) in several reverse micelle (RM) systems using cationic, anionic, and nonionic surfactants. The confinement effects on anion vibrational spectra and dynamics in aqueous RMs depend on the charge of the surfactant that is used to form the RMs. Spectra and VER dynamics of ferrocyanide are not significantly altered in the limited number of RMs in which it could be solubilized. The static spectra of ferricyanide suggest an environment that is most bulklike in anionic RMs and least bulklike in cationic RMs. The dynamics of ferricyanide are slower in cationic RMs and indistinguishable from the bulk in nonionic RMs. The VER dynamics and static spectra of SNP are indistinguishable from the bulk in anionic RMs, but much slower in cationic RMs. This suggests a strong surfactant-solute repulsion in the former and an attraction in the latter. Broad static spectra and probe frequency dependent dynamics are seen for SNP in nonionic RMs, indicating an inhomogeneous distribution of environments. Similar measurements were carried out for SNP in mixtures of water and a model compound containing only the hydrophilic portion of the nonionic surfactants in which RMs are not formed. The results closely resemble those observed for SNP in nonionic RMs and provide evidence that in the latter water penetrates the interface and hydrates the ethylene oxide groups before forming a water pool. The results are consistent with the explanation that Coulombic forces determine the anion location. The anions are repelled to the interior of the water pool, which has a bulklike environment in anionic RMs, and are attracted to the interface in cationic RMs, resulting in a strong interaction with the surfactant. The solute location in the nonionic RMs depends on the hydrophilic nature of the probe, with ferrocyanide and ferricyanide being more hydrophilic than SNP. These results and the dependence on surfactant charge are similar to those reported for azide.     

Enantiomer ratio of MK-0767 in humans and nonclinical species

MK-0767, (+/-)-5-[(2,4-dioxothiazolidin-5-yl)methyl]-2-methoxy-N-[[(4-trifluoromethyl)phenyl]methyl]benzamide, is a thiazolidinedione-containing dual peroxisome proliferator-activated receptor (PPAR) alpha/gamma agonist that has been studied as a potential treatment for patients with type 2 diabetes. MK-0767 contains a chiral center at the C-5 position of the thiazolidinedione ring and was being developed as the racemate, due to the rapid interconversion of its enantiomers in biological samples. In the present work the in vitro and in vivo concentration ratios of the (+)-(R) to (-)-(S) enantiomers of MK-0767 were determined in plasma from humans (in vitro only) and nonclinical species used in the toxicological evaluation of rac-MK-0767, namely CD-1 mice, Sprague-Dawley rats, beagle dogs, New Zealand white rabbits, and rhesus monkeys. The R/S ratio was determined by chiral liquid chromatography/tandem mass spectrometry. Species differences were observed in the in vitro and in vivo enantiomeric ratios, as well as differences between in vitro and in vivo in some species. The in vitro R/S ratio was similar in dogs and humans (approximately 1.5-1.7). In rats and monkeys, the ratio was approximately unity, both in vitro and in vivo. In mice, the ratio was higher in vitro (approximately 1) than in vivo (approximately 0.6), while in rabbits it was higher in vivo (approximately 1) than in vitro (approximately 0.5). These results suggested that differential binding of the MK-0767 enantiomers to plasma and tissue proteins and other macromolecules may be affecting the R/S ratio both in vitro and in vivo, since in protein-free systems MK-0767 exists as the racemate.     

EFFECT OF EXPOSURE TO LIGHT ON ENZYME ACTIVITIES and TRYPTOPHAN METABOLITES OF THE KYNURENINE PATHWAY IN WISTAR, IN HETEROZYGOUS and HOMOZYGOUS ADULT and NEWBORN GUNN RATS

Abstract— The purpose of this study was to determine the influence of phototherapy used in the treatment of hyperbilirubinemia in infants, on tryptophan metabolism and on enzyme activities involved along the kynurenine pathway in Wistar, icteric homozygous and nonicteric heterozygous Gunn rats after an intraperitoneal loading of 1.0 g/kg body weight L-tryptophan before and after exposure to visible light. The total mean 24-h excretion of the tryptophan metabolites in the groups of the Wistar and heterozygous Gunn rats was higher in females than in males and higher than in homozygous groups before phototherapy. Only after exposure to light did the groups of Wistar and heterozygous Gunn rats of both sexes show a decrease in the total excretion of the metabolites. The activities of tryptophan pyrrolase and kynureninase in liver and kynurenine aminotransferase in liver and kidneys were assayed in each group of rats. Male and female Wistar and heterozygous Gunn rats showed a higher activity of tryptophan pyrrolase than the groups of homozygotes in agreement with the data of the metabolites excreted. No difference in enzyme activities was found between the groups of heterozygous and homozygous neonates before and after phototherapy. Phototherapy did not seem to influence these enzyme activities.     

DFT calculations of the ionization potentials and electron affinities of serinamide

Adiabatic and vertical ionization potentials (IPs) and valence electron affinities (EAs) of serinamide in the gas phase have been determined using density functional theory (DFT) B3LYP, B3P86, and B3PW91 methods with the 6‐311++G** and 6‐311G** basis sets, respectively. IPs and EAs of serinamide in solution have been calculated with the B3LYP method using the 6‐311++G** and 6‐311G** basis sets. Eight possible conformers of serinamide and its charged states in the gas phase have been optimized employing the DFT B3LYP method with 6‐311++G** and 6‐311G** basis sets, respectively. All the adiabatic and vertical ionization potentials (AIPs and VIPs) of eight serinamide conformers in our work are positive values, whether in the gas phase or in solutions; the IPs in solutions are smaller than the results in the gas phase and decrease with increased dielectric constants in solutions. This finding indicates that the cationic states in solutions are more stable than those in the gas phase. All EAs of eight serinamide conformers are negative values in the gas phase, indicating that the anionic states are unstable with respect to electron autodetachment, both adiabatically and vertically. In contrast, all other adiabatic electron affinities (AEAs) are negative values in solutions except for 6S in water; 7S in chloroform, acetone, and water; and 8S in acetone and water, and increase with increasing of dielectric constants in solutions. All vertical electron affinities (VEAs) are negative values in solutions; however, no good rule has been found for these values in solutions. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006     

Expression patterns of betaig-h3 in chondrocyte differentiation during endochondral ossification

betaig-h3 is a TGF-beta-induced extracellular matrix protein which is expressed in many tissues including bones and cartilages. In previous reports, we showed that betaig-h3 mediates cell adhesion and migration and, especially in bones, negatively regulates the mineralization in the end stage of endochondral ossification. Here, to elucidate the expression pattern and role of betaig-h3 in chondrocyte differentiation, ATDC5 chondrocytes and embryonic and postnatal mice were used for in vitro differentiation studies and in vivo studies, respectively. betaig-h3 was strongly induced by the treatment of TGF-beta1 and the expression level of betaig-h3 mRNA and protein were highly expressed in the early stages of differentiation but decreased in the late stages in ATDC5. Furthermore, the patterns of TGF-beta1, -beta2, and -beta3 mRNA expression were concurrent with betaig-h3 in ATDC5. betaig-h3 was deeply stained in perichondrium (PC), periosteum (PO), and prehypertrophic chondrocytes (PH) through the entire period of endochondral ossification in mice. betaig-h3 was mainly expressed in PC and PH at embryonic days and obviously in PH in postnatal days. These results suggest that betaig-h3 may play a critical role as a regulator of chondrogenic differentiation in endochondral ossification.     

Hydrogen bonding and cation coordination effects in primary and secondary amines dissolved in carbon tetrachloride

Raman and infrared spectroscopy were used to investigate hydrogen-bonding interactions and cation coordination effects in solutions of lithium triflate (LiCF3SO3) dissolved in two primary amines, hexylamine (HEXA) and N,N-dimethylethylenediamine (DMEDA), and in a secondary amine, dipropylamine (DPA). Strong intermolecular hydrogen-bonding interactions and weaker intramolecular hydrogen-bonding interactions that occur only in DMEDA were spectroscopically distinguished in a comparison of pure HEXA, pure DMEDA, and the dilute solutions of these amines in CCl4. The spectroscopic shifts in intensity and frequency in the NH stretching region of DPA and DPA diluted in CCl4 were similar to those of HEXA. Dilute electrolyte solutions in carbon tetrachloride were prepared to analyze specifically the cation coordination effect. In these solutions, limited intermolecular hydrogen-bonding interactions are present, and the observed spectral shifts correspond primarily to the cation-induced shifts. The symmetric SO3 stretching region of the triflate anion was investigated to probe further the coordination of the cation. The local structures of the triflate ions and the amine groups in the electrolyte solutions dissolved in CCl4 are similar to the local structures in the corresponding amine-salt crystals previously reported by us.