Search NEL Online

Journal Article 2006; 27(Suppl 2): 130-133 PubMed PMID: 17159797 Citation  Keywords:  Adult, Chromatography, High Pressure Liquid:methods, Dose-Response Relationship, Drug, Female, Humans, Male, Methadone:analogs & derivatives, Molecular Conformation, Opioid-Related Disorders:blood, Sensitivity and Specificity,.   

OBJECTIVES: A stereoselective HPLC method was developed to separate and quantify both enantiomers of methadone and its main metabolite EDDP in serum and urine. The method was used to establish that there is a relationship between the dose of methadone prescribed and its serum concentration as well as urine excretion of methadone and its metabolite enantiomers.

METHODS: The chiral alpha1-glycoprotein stationary phase was used for enantioseparation of (R)-methadone, (S)-methadone and (R)-EDDP (S)-EDDP. The enantiomers of methadone and EDDP were extracted from urine and serum by a simple solidphase procedure.

RESULTS: The validated method was applied to the analysis of 31 serum and urine samples obtained from methadone-maintained outpatients (65% male, age 28.8+/-4; methadone dose 146+/-47 mg). A significant correlation (Pearson) r=0.67 (p<0.001) between methadone dose and serum concentration of (R)-methadone was found. Due to the large variation in results obtained from analysis of the subjects' urine specimens, no statistically significant relationship between methadone dose and urine excretion of methadone and EDDP enantiomers was established. The rate of R/S methadone (1.38 in serum, 2.43 in urine) and R/S EDDP (0.83 in urine) confirmed stereoselectivity in methadone metabolism with high individual variability.

CONCLUSIONS: The enantioselective evaluation of serum methadone concentration might be an interesting tool in methadone maintenance programme. On the other hand, the urinary excretion of methadone and EDDP enantiomers is not reliable as marker of methadone compliance but could be useful for monitoring individual metabolism or for studying the stereoselectivity in pharmacokinetics and metabolism of methadone....

Read abstract

Comparative Study 2006; 27(Suppl 2): 31-34 PubMed PMID: 17159774 Citation  Keywords:  Hyaluronic Acid:chemistry, Hydrogen Peroxide:pharmacology, Manganese Compounds:pharmacology, Models, Biological, Molecular Weight, Oxides:pharmacology, Peroxynitrous Acid:chemical synthesis, Viscosity,.   

OBJECTIVES: This contribution presents the results of the kinetics of HA degradation by peroxynitrite, which represents one of the main reactive oxygen species degrading various biomacromolecules under inflammatory conditions.

METHODS: Two simple procedures have been adapted to prepare sodium peroxynitrite: the first containing an excess of H(2)O(2), and the second in which the H(2)O(2) excess had been decomposed by MnO(2) treatment. The kinetics of hyaluronan degradation by action of peroxynitrite was monitored by rotational viscometry.

RESULTS: High-molecular-weight hyaluronan was degraded by peroxynitrite. The degradation was increased in the presence of ONOO(-) previously treated by MnO(2) in order to remove residual hydrogen peroxide. One of the reasons of this finding could be that by the action of the residual metal the pathway of ONOO(-) decomposition starts to be manifested immediately on mixing traces of metals originally present in the HA sample with the ions of manganese.

CONCLUSIONS: Trace amounts of transition metal(s) should be taken into consideration on evaluating the experimental results. Purchase of the marketed peroxynitrite product appears to be the appropriate approach to simplify and standardize the quality of ONOONa....

Read abstract

Journal Article 2006; 27(1-2): 219-224 PubMed PMID: 16648810 Citation  Keywords:  3-Hydroxysteroid Dehydrogenases:genetics, Adrenal Cortex Hormones:metabolism, Alleles, Child, China:epidemiology, Female, Gene Frequency, Genotype, Gonadal Steroid Hormones:blood, Humans, Insulin Receptor Substrate Proteins, Molecular Sequence Data, Phosp.   

OBJECTIVES: In order to investigate whether the variances in the candidate genes (Insulin receptor substrate IRS-1, beta3-adrenergic receptor ADRB3, 3 beta-hydro-xysteroid dehydrogenase HSD3B2, glucocorticoid receptor GRL and 21-hydroxylase CYP21) which affect the metabolism of adrenal steroids hormone and body composition, are associated with precocious puberty in Chinese girls.

METHODS: PCR-RFLP analysis method was applied in the typing of six activity SNPs in five genes in two groups: 176 precocious puberty girls as case and 192 healthy girls as control.

RESULTS: The typing results showed that the frequencies of the allele CYP21 L282 polymorphism were 32.7% and 32.6% in case and control groups (P=0.518), respectively. For IRS-1 R972, they were 0.6% in cases and 2.3% in controls (P=0.043), for ADRB3 R64, 13.6% in cases and 12% in controls (P=0. 378), and for GRL S363, 7.4% in cases and 5.73% in controls (P=0.335). No sample in the two groups carries the variation of CYP21 I172N and HSD3B2 L236S.

CONCLUSION: Among these six activity SNPs in five candidate genes, IRS-1 972R was statistically associated with the onset time of puberty in Chinese girls. In order to confirm whether the candidate genes have any other activity SNPs that are associated with the onset time of puberty in Chinese girls, resequencing of these candidate genes is needed in following time....

Read abstract

Journal Article 2005; 26(3): 247-252 PubMed PMID: 15990730 Citation  Keywords:  Animals, Copper:chemistry, Gonadotropin-Releasing Hormone:chemistry, Metals, Heavy:chemistry, Nickel:chemistry, Nuclear Magnetic Resonance, Biomolecular, Protons, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization,.   

: MALDI-TOF mass spectrometry, 1H NMR spectrometry, the continuous variation method and molecular modeling by MM3 calculation confirmed our earlier studies showing that gonadotropin-releasing hormone (GnRH) forms complex with copper(II) ion with the binding ratio 1:1. The copper(II) complex formed at physiological pH has a square planar configuration and GnRH complexes with nickel(II) and cobalt(II) ions are less stable than that of copper(II)....

Read abstract  Full text PDF

Journal Article 2005; 26(3): 237-241 PubMed PMID: 15990728 Citation  Keywords:  Animals, DNA:chemistry, Entropy, Evolution, Molecular, Humans, Models, Chemical, Nucleic Acid Conformation, Peptides:chemistry, Promoter Regions, Genetic, Protein Binding, Protein Conformation, Transcription Factors:chemistry,.   

PROBLEM: Gerontology observations show that ageing of organism is accompanied by the decrease of the chromatin activity and slowing down of the protein synthesis. Natural regulatory oligopeptides and their synthetic analogues take part in the activation of chromatin and normalise rate of the protein synthesis in cultured tissues. Regulatory peptides significantly enhance longevity.

OBJECTIVES: The objective of this work is to find a possible molecular mechanism by which the regulatory peptides influence the part of genetic system is responsible for initiation of protein synthesis in higher organisms.

METHODS: An interdisciplinary approach was used to address the problem. The work involved not only medical scientists and biologists, but also specialists in biopolymer chemistry, and mathematicians for statistical analysis of information interaction of amino acid and nucleotide sequences.

CONCLUSIONS: The structures and metrics of peptides and the DNA double-helix cause the recognition and complementary binding of a regulatory peptide with DNA functional groups at the interface of the major groove. We have used complementary binding model to find a possible base pair sequence ATTTTC for specific binding of synthetic tetrapeptide epitalon. This base pair block and its reverse complement were found repeatedly in the promoter region of telomerase. A comparison of statistical information content of peptides and oligonucleotide sequences shows that these two classes of biopolymers are information carriers and. exchange the information to initiate the gene transcription....

Read abstract  Full text PDF

Comparative Study 2005; 26(2): 89-97 PubMed PMID: 15855878 Citation  Keywords:  Analysis of Variance, Animals, Base Sequence, Hemolymph:metabolism, Humans, Molecular Sequence Data, Morphine:metabolism, Nephropidae:metabolism, Nerve Tissue Proteins:metabolism, Nervous System:metabolism, Nitric Oxide:secretion, Nitric Oxide Synthase:me.   

OBJECTIVES: The study was designed to determine if morphine was present in lobster tissues. It was also important to determine, as in other animals, if its levels would change in response to stress. In this regard, it was also important to determine if lobster immune and neural tissues express the mu opiate receptor subtype, which was coupled to constitutive nitric oxide synthase derived nitric oxide release.

METHODS: Homarus americanus were used in these experiments. Morphine was purified in lobster tissues via high pressure liquid chromatography coupled to UV detection. It was quantified via radioimmunoassay (RIA) and was identified via quadruple time of flight - mass spectrometry. Animals were subject to 2 forms of trauma, namely pereiopod-ablation or lipopolysaccaride (LPS) - injection, and morphine levels determined in nerve cord or hemolymph. Real-time nitric oxide production was determined via an amperometric probe. RT-PCR was used to determine the presence of a micro opiate receptor transcript.

RESULTS: In Homarus americanus hemolymph and nerve cord morphine was found. RIA revealed morphine levels of 3.36 pg/mg +/ - 0.48 SEM (N=8) in nerve cord and 717.88 pg/ml +/ - 56.77 SEM (N=58) in hemolymph. In stressed (pereiopod-ablated or LPS-injected) animals, the endogenous morphine levels initially increased significantly by 24% for hemolymph and 48% for nerve cord. By day 5, the stressed and control values for endogenous morphine, in both tissues, was lower and non-distinguishable. In both hemocytes and neural cells, morphine, not met-enkephalin, stimulated constitutive nitric oxide release in a naloxone antagonizable manner, demonstrating a mu opiate receptor mediated phenomenon and suggesting the presence of the mu opiate receptor subtype, micro3, since it is opiate alkaloid selective and opioid peptide insensitive. RT-PCR revealed the presence of a micro opiate receptor transcript in Homarus neural and immune tissues, which exhibits a 100% sequence identity with its human counterpart.

CONCLUSION: Taken together, after eliminating all sources of contamination, morphine is present in lobster tissues, potentially demonstrating hormonal and neurotransmitter functions that are involved in the animals' stress response....

Read abstract  Full text PDF

Journal Article 2005; 26(1): 61-66 PubMed PMID: 15726022 Citation  Keywords:  Chromatography, Liquid, Kinetics, Malondialdehyde:chemistry, Mass Spectrometry, Melatonin:chemistry, Molecular Weight, Spectrometry, Mass, Electrospray Ionization, Temperature, Thermodynamics,.   

OBJECTIVES: A purpose of this study is to determine whether melatonin, a novel antioxidant, can interact with malondialdehyde in an in vitro condition.

METHODS: The reaction kinetics and thermodynamics of this reaction have been performed and a new product has been identified using liquid chromatography onlining with mass spectrometry.

RESULTS: A new product generated with an interaction of melatonin and malondialdehyde has been identified to be a three-ring structure with a molecular weight 286, which has the specific wavelength absorption with the maximum at 345 nm. The reaction was completed within a few minutes and the product was proportional to the concentrations of the reactants. Based on its molecular weight and the deduced structure of the new product, we speculate that this reaction occurs between one melatonin molecule and one malondialdehyde and to form a 3 ring conjugated adduct.

CONCLUSION: This is the first report to show that melatonin directly interacts with malondialdehyde to form a new product. The findings suggest that melatonin may detoxify unsaturated carbonyls and protect against cellular damage induced by oxidative stress....

Read abstract  Full text PDF

Journal Article 2004; 25(3): 184-190 PubMed PMID: 15349083 Citation  Keywords:  Alternative Splicing, Animals, Base Sequence, Bivalvia:genetics, Cilia:drug effects, Enkephalin, Ala(2)-MePhe(4)-Gly(5)-:pharmacology, Ganglia, Invertebrate:drug effects, Genetic Variation, Haloperidol:pharmacology, Molecular Sequence Data, Morphine:pharm.   

OBJECTIVES: The study sought to determine how dopamine controls ganglionic processes involved with modulating lateral cilia beating via the peripheral branchial nerve.

METHODS: The lateral cilia found on the gill filaments exhibit metachronal ciliary beating determined stroboscopically. Novel opiate receptors were determined pharmacologically and demonstrated by RT-PCR and sequence analysis of total RNA from Mytilus edulis visceral ganglia.

RESULTS: Dopamine applied to the visceral ganglion inhibits the activity of lateral cilia in a concentration and haloperidol sensitive manner. Morphine or DAMGO significantly enhances ciliary beating in a naloxone sensitive manner, whereas L-NAME, a nitric oxide synthase inhibitor, only antagonized morphine's action. SNAP, a nitric oxide donor, also enhanced lateral ciliary beating rates. Supporting the observation, i.e., morphine sensitive nitric oxide enhancement of ciliary beating and DAMGO insensitive, that two different mu opiate receptors are present in this tissue, a 602 bp fragment of the human micro 3 opiate receptor and a 935 bp fragment, designated micro 4 have been demonstrated.

CONCLUSIONS: The lateral epithelium of the gill is innervated by serotonergic, cilioexcitatory neurons and dopaminergic, cilioinhibitory neurons, originating in the visceral ganglion. This data supports previous reports that demonstrate inhibiting ganglionic dopamine release allows the serotonin signals to prevail uncontrolled, enhancing ciliary rates. Supporting the observation that two different mu opiate receptors are present in this tissue, evidence is presented that identifies a 602 bp fragment of the human micro 3 opiate receptor and a 935 bp fragment, designated micro 4. Overall, the data strongly suggests that the two alternatively spliced mu opiate receptors may be involved in the physiological regulation of lateral ciliary activity in the visceral ganglia via dopamine and nitric oxide....

Read abstract  Full text PDF