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Migraine is a neurological disorder that affects the central nervous system causing painful attacks of headache. A genetic vulnerability and exposure to environmental triggers can influence the migraine phenotype. Migraine interferes in many facets of people’s daily life including employment commitments and their ability to look after their families resulting in a reduced quality of life. Identification of the biological processes that underlie this relatively common affliction has been difficult because migraine does not have any clearly identifiable pathology or structural lesion detectable by current medical technology. Theories to explain the symptoms of migraine have focused on the physiological mechanisms involved in the various phases of headache and include the vascular and neurogenic theories. In relation to migraine pathophysiology the trigeminovascular system and cortical spreading depression have also been implicated with supporting evidence from imaging studies and animal models. The objective of current research is to better understand the pathways and mechanisms involved in causing pain and headache to be able to target interventions. The genetic component of migraine has been teased apart using linkage studies and both candidate gene and genome-wide association studies, in family and case-control cohorts. Genomic regions that increase individual risk to migraine have been identified in neurological, vascular and hormonal pathways. This review discusses knowledge of the pathophysiology and genetic basis of migraine with the latest scientific evidence from genetic studies.

Prior to the completion of the human genome project, the human genome was thought to have a greater number of genes as it seemed structurally and functionally more complex than other simpler organisms. This along with the belief of “one gene, one protein”, were demonstrated to be incorrect. The inequality in the ratio of gene to protein formation gave rise to the theory of alternative splicing (AS). AS is a mechanism by which one gene gives rise to multiple protein products. Numerous databases and online bioinformatic tools are available for the detection and analysis of AS. Bioinformatics provides an important approach to study mRNA and protein diversity by various tools such as expressed sequence tag (EST) sequences obtained from completely processed mRNA. Microarrays and deep sequencing approaches also aid in the detection of splicing events. Initially it was postulated that AS occurred only in about 5 of all genes but was later found to be more abundant. Using bioinformatic approaches, the level of AS in human genes was found to be fairly high with 35-59 of genes having at least one AS form. Our ability to determine and predict AS is important as disorders in splicing patterns may lead to abnormal splice variants resulting in genetic diseases. In addition, the diversity of proteins produced by AS poses a challenge for successful drug discovery and therefore a greater understanding of AS would be beneficial.

BF2 Chelated azadipyrromethene dyes fluoresce in the near infrared and have potential applications in photodynamic therapy. When irradiated above 600nm these aza-BODIPY compounds react with triplet O2 in the body to form a reactive singlet oxygen species which leads to cell death. A small library has been synthesized of these potential PDT agents via a four step process, with varying substituents on the aromatic ring of the starting benzaldehyde and acetophenone. In vitro studies on HeLa cells have revealed an effective photosensitive compound with low dark cytotoxicity and promotion of apoptotic cell death when exposed to light.

Polarization modulation infrared linear dichroism (PM-IRLD) and ultrarapid-scanning Fourier transform infrared spectroscopy (URS-FTIR) have been used to characterize the evolution of molecular orientation and microstructure during and following the step deformation of amorphous poly(ethylene terephthalate) (PET) above and below its glass transition temperature. The combined use of these techniques allowed a high sensitivity and an unprecedented 10 ms time resolution for the characterization of irreversible polymer deformation using infrared spectroscopy. PM-IRLD results show that the 1410 cm-1band of PET, often used as a thickness standard, presents a significant dichroism even at low draw ratios. Using this band, the relaxation kinetics of the phenyl ring was directly shown, for the first time, to be similar to that of the glycol group in amorphous PET. These results suggest that the relaxation proceeds mainly via cooperative motions involving at least one repeat unit and not only through rotations around the flexible CH2−CH2and CH2−O bonds. The real-time study of the cold drawing of glassy amorphous PET by URS-FTIR showed that a large gauche-to-trans conversion (from ∼15% to 60% of trans conformers) of the glycol groups occurs during the neck propagation. These trans conformers possess a very large and stable molecular orientation. Nevertheless, spectral analysis revealed that the “mesomorphic” phase, rather than the truly (all-trans) crystalline structure, is produced during cold drawing of PET at room temperature.

Lipopolysaccharide (LPS)-activated monocytes and macrophages produce large quantities of pro-interleukin (IL)-1beta but externalize little mature cytokine. Efficient post-translational processing of the procytokine occurs in vitro when these cells encounter a secretion stimulus such as ATP, cytolytic T cells, or hypotonic stress. Each of these stimuli promotes rapid conversion of 31-kDa pro-IL-1beta to its mature 17-kDa species and release of the 17-kDa cytokine. In this study, two novel pharmacological agents, CP-424,174 and CP-412,245, are identified as potent inhibitors of stimulus-coupled IL-1beta post-translational processing. These agents, both diarylsulfonylureas, block formation of mature IL-1beta without increasing the amount of procytokine that is released extracellularly, and they inhibit independently of the secretion stimulus used. Conditioned medium derived from LPS-activated/ATP-treated human monocytes maintained in the absence and presence of CP-424,174 contained comparable quantities of IL-6, tumor necrosis factor-alpha (TNFalpha), and IL-1RA, but 30-fold less IL-1beta was generated in the test agent's presence. As a result of this decrease, monocyte conditioned medium prepared in the presence of CP-424,174 demonstrated a greatly diminished capacity to promote an IL-1-dependent response (induction of serum amyloid A synthesis by Hep3B cells). Oral administration of CP-424,174 to mice resulted in inhibition of IL-1 in the absence of an effect on IL-6 and TNFalpha. These novel agents, therefore, act as selective cytokine release inhibitors and define a new therapeutic approach for controlling IL-1 production in inflammatory diseases.

The subjective and physiological effects of intravenously administered caffeine and nicotine were compared in nine subjects with histories of using caffeine, tobacco, and cocaine. Subjects abstained from tobacco cigarette smoking for at least 8 h before each session. Dietary caffeine was eliminated throughout the study; however, to maintain consistency with the nicotine intake, subjects were administered caffeine (150 mg/70 kg b.i.d.) in capsules, with the last dose administered 15 to 18 h before each session. Under double-blind conditions, subjects received placebo, caffeine (100, 200, and 400 mg/70 kg), and nicotine (0.75, 1.5, and 3.0 mg/70 kg) in mixed order. Physiological and subjective data were collected before and repeatedly after drug or placebo administration. Compared with the highest dose of caffeine, the highest dose of nicotine produced greater subjective ratings on a number of scales. At doses that produced comparable ratings of drug effect (1.5 mg/70 kg of nicotine and 400 mg/70 kg of caffeine), both drugs produced similar increases in ratings of good effect, liking, high, stimulated, and bad effect. Nicotine showed a somewhat faster time to peak subjective effects than caffeine (2 versus 4 min). Subjective ratings that differentiated caffeine and nicotine were ratings of rush, blurry vision, and stimulant identification (elevated by nicotine) and ratings of unusual smell and/or taste (elevated by caffeine). Both caffeine and nicotine decreased skin temperature and increased diastolic blood pressure; however, caffeine decreased whereas nicotine increased heart rate. The study documents both striking similarities and some notable differences between caffeine and nicotine, which are among the most widely used mood-altering drugs.

Accelerated infusions are potentially useful in the investigation of pharmacokinetic linearity. However, little information exists to validate this technique or to demonstrate its limitations. This investigation was performed to determine whether accelerated infusion regimens reliably estimate the range of pharmacokinetic linearity for molecules of varying pharmacokinetic properties, to evaluate the ability of accelerated infusions to identify pharmacokinetic nonlinearity, and to validate the accelerated infusion technique using compounds with known pharmacokinetic parameters. Simulations incorporating accelerated infusion as the input function resulted in the anticipated concentration-time profiles that contained an initial lag phase before reaching a linear slope. This lag phase increased with increasing distributional volume and in some instances was sufficiently great to obscure or prevent the linear portion of the profile. These simulations also revealed that clearance estimated from the apparently linear portion of the concentration-time profile can be erroneous under some conditions, as for large-volume compounds. Simulations of structured nonlinearity produced the predicted profiles for compounds with low to moderate volumes of distribution while demonstrating that modeling of data derived from compounds with large volumes of distribution may be inaccurate. Finally, experiments using accelerated infusions with various test compounds further demonstrated the usefulness of this technique while presenting limits imposed on the interpretation of the data. The results of this investigation indicate that the accelerated infusion may be used to determine pharmacokinetic linearity for compounds within certain pharmacokinetic boundaries, but that appropriate caution should be exercised in the extent of interpretation that should be extracted from such studies.

The benzodiazepine receptor ligand U-78875 [3-(5-cyclopro pyl-1,2, 4-oxadiazol-3-yl)-5-(1-methylethyl)imidazol(1, 5-a)quinoxalin-4(5H)-o-ne] was studied in rats trained to discriminate i.p. 1.0 mg/kg lorazepam, 1.0 mg/kg diazepam, or 10 mg/kg pentobarbital, and baboons trained to discriminate oral 1.8 mg/kg lorazepam or 10 mg/kg pentobarbital. U-78875 doses were 0.01 to 10 mg/kg i.p. in rats and 0.32 to 56 mg/kg orally in baboons. U-78875 occasioned drug-appropriate responding in pentobarbital-trained (ED50 = 1.8 mg/kg) and diazepam-trained (ED50 = 0.056 mg/kg) rats, but it occurred in only one pentobarbital-trained baboon and not in the majority of lorazepam-trained baboons or rats. In baboons that generalized to U-78875, discriminative effects were antagonized by flumazenil. The interaction of U-78875 with pentobarbital, diazepam, and lorazepam revealed further differences in its behavioral effects. U-78875 potentiated the effects of pentobarbital, even in baboons that did not generalize to U-78875, but U-78875 had little effect in combination with diazepam. In lorazepam-trained animals that did not generalize to it, U-78875 antagonized lorazepam's effects, but U-78875 neither antagonized nor potentiated lorazepam in animals that did generalize to U-78875. Thus, although U-78875 generally functioned as a benzodiazepine agonist in pentobarbital- and diazepam-trained animals, its unique effects in lorazepam-trained animals appear to reflect its in vitro profile as a partial agonist.

Although caffeine is the most widely used behaviorally active drug in the world, caffeine physical dependence has been only moderately well characterized in humans. Four double-blind experiments were conducted in independent groups of healthy participants to assess the conditions under which withdrawal symptoms occur upon cessation of low to moderate doses of caffeine. In experiment 1, there was no evidence that the range or magnitude of caffeine withdrawal symptoms differed when 300 mg of caffeine was consumed as a single dose in the morning versus 100 mg at three time points across the day. In experiment 2, both the range and severity of withdrawal increased as a function of caffeine maintenance dose (100, 300, and 600 mg/day), with even the lowest dose (100 mg) producing significant caffeine withdrawal. Experiment 3 showed that when individuals were maintained on 300 mg caffeine/day and tested with a range of lower doses (200, 100, 50, 25, and 0 mg/day), a substantial reduction in caffeine consumption (

A detailed investigation of the dissolution of alkali metal uranates in carbonate melts has been performed for the first time. The solubilities are reported for three alkali metal (Li, Na and K) mono- and diuranates, between 723 and 1073 K in alkali metal carbonate mixtures, and ranged from 20 to 275 wt ppm. The solvents used were the carbonate eutectics Li–Na, Li–K and Li–Na–K, and the low melting carbonate liquid Na–K. The well-known V-shaped behaviour of the solubilities of binary oxides in molten sulfates and carbonates with basicity increase was here observed for mono- and diuranates(VI). The explanation in terms of acid–base behaviour holds, the acidity and solubilities decreasing initially with temperature increase and then reversing as the melt becomes more basic. Uranate dissolution is thus both a physical and chemical process and hence from these data the solubilisation enthalpy in both acidic and basic melts was obtained for all six uranates(VI) in the four melts. Further, the oxidation of UO2 to form uranates in molten carbonates must proceed by mass transfer of an oxidising species through a layer of uranates formed on the urania surface.

The problem of the uniqueness of parameters obtained during fitting of experimental spectra containing closely overlapping bands has been evaluated, since conventional methods of fitting do not produce reliable results. It is here shown that, despite the difficulties inherent in both the formal mathematical problem and its numerical solutions, typical and representative spectra can be resolved unambiguously within a reasonably chosen theoretical model. Reliable values of the parameters of the model, including parameters of band shape, can also be obtained. A random search method of global minimisation of a function with a significant number of arguments is derived. A program and algorithm to implement this method for spectra decomposition have been developed. The program allows the microdynamics of liquids to be obtained directly upon performing numerical Fourier transformations on a model (theoretical) time correlation function together with using model spectra obtained thereby in each fitting step. A model spectrum for any desired accuracy and frequency range can hence be generated without the unavoidable errors inherent in conventional methods. The apparatus function of the spectrophotometer is also now readily incorporated. Using the algorithm, the parameters of the microdynamics of acetonitrile molecules are obtainable for the first time upon decomposition of its ν2 Raman vibration, and a value of 0.069 was obtained for the dimensionless modulation speed in liquid acetonitrile. This method has also enabled for the first time the detection of molecules in the second solvation shell around Li+ in acetonitrile, from within its Raman spectrum.

The current study examined behavioral effects and possible development of physical dependence after once-daily doses of zolpidem (0, 1.0, 3.2, 10.0, 32.0 mg/kg intragastrically [i.g.]) in three baboons. Each dose was administered for 17 days and then the dose was increased; the 32.0 mg/kg dose was administered for 27 days. Baboons had access to food pellets for 20 hr/day beginning 15 min after dosing. Each day, baboons were presented with a fine motor task. Observation sessions were conducted 1 hr after dosing on days 1, 10, 12 and 14 of each dose condition and after termination of drug dosing. On days 10 and 14 of each dose condition, vehicle and flumazenil (5 mg/kg i.m.) were administered, respectively. Zolpidem increased the number of pellets obtained by two of three baboons. Vomit and/or retch and grimace (signs believed to be indicative of abdominal discomfort) were observed in one or two baboons during all zolpidem dose conditions (1.0-32.0 mg/kg). Time to complete the fine motor task increased dose-dependently in all three baboons, and incoordination was observed during the task in two baboons at 10.0 and 32.0 mg/kg. Analysis of blood plasma showed that measurable levels of zolpidem were present 24 hr after dosing in all drug conditions. The signs of flumazenil-precipitated withdrawal were summarized on a 9-point scale. Scores ranged from 1 to 5 in the 1.0 mg/kg condition, from 2 to 5 in the 3.2 and 10.0 mg/kg conditions and from 4 to 6 in the 32.0 mg/kg condition. Signs that were considered intermediate in severity were observed. Specifically, tremor, jerk and/or rigidly braced posture was observed in one baboon at 1.0 mg/kg, two baboons at the next two doses and all three baboons at 32.0 mg/kg. Vomit and/or retch also occurred in two baboons at dose conditions above 1.0 mg/kg. Discontinuation of zolpidem dosing after 78 to 79 days resulted in mild withdrawal signs (e.g., number of pellets obtained were lower and number of 1-min intervals increased in which eyes were closed, or in which lying down, head lower than torso posture and/or withdrawn posture were observed) on the first day in two baboons. The peak withdrawal scores were 4 or 5 on days 5 to 10; two baboons vomited and/or retched and all three baboons showed tremor, jerk and/or rigidly braced posture. Thus, zolpidem produced physical dependence under once-daily dosing conditions, and the severity of the withdrawal syndrome can be characterized as intermediate.

The discriminative stimulus effects of benzodiazepines often have been indistinguishable from those of barbiturates or other sedative/anxiolytics. However, baboons and rats trained to discriminate lorazepam did not reliably generalize to pentobarbital in previous studies, although animals comparably trained to discriminate pentobarbital reliably generalized to lorazepam. The present study investigated the generalization profile for a variety of anxiolytic, sedative and other drugs in baboons trained to discriminate oral lorazepam (1.8 mg/kg). Triazolam, alprazolam, diazepam, midazolam, bromazepam, temazepam and nordiazepam occasioned >80% of total responses on the lorazepam-paired lever, in that order of potency, 60 min after oral dosing; chlordiazepoxide did so in three of five baboons. However, barbiturates (amobarbital, hexobarbital, methohexital, pentobarbital, phenobarbital, secobarbital) and methypryIon occasioned lorazepam-appropriate responding in only one or two baboons. Testing barbiturates at different pretreatment times (amobarbital, hexobarbital, pentobarbital or secobarbital) or by an i.m. route of administration (methohexital, pentobarbital) did not produce an increase in generalization. Neither other classic sedatives/anxiolytics (chloral hydrate, clomethiazole, ethanol, methaqualone, meprobamate, triclofos), nor anticonvulsants (phenytoin, valproic acid), nor drugs from other pharmacological classes shared discriminative-stimulus effects with lorazepam. These results, together with those from previous studies in which lorazepam or another benzodiazepine served as the training stimulus, indicate that lorazepam training results in a more selective generalization profile with respect to sedative/anxiolytic drugs than does training with other benzodiazepines.

The subjective and physiological effects of intravenously administered cocaine and nicotine were compared in 10 cigarette-smoking cocaine abusers. Subjects abstained from smoking at least 8 h before each session. Under double blind conditions, subjects received placebo, cocaine (10, 20, and 40 mg/70 mg), or nicotine (0.75, 1.5, 3.0 mg/70 kg) in mixed order. Physiological and subjective data were collected before and repeatedly after each intravenous drug administration. Subjects also completed a drug versus money multiple-choice procedure in which they chose between that day's drug and 44 monetary values. Both drugs increased blood pressure and heart rate and decreased skin temperature. Nicotine showed a more rapid onset of subjective effects than cocaine. Overall, although both cocaine and nicotine increased subjective ratings of "drug effect", "rush", "good effects", "liking", "high", and "stimulated", only nicotine increased ratings of "bad effects" and "jittery". Although the highest nicotine dose produced greater effects than the highest cocaine dose on most subjective measures, the highest cocaine dose produced somewhat greater ratings of drug liking. At doses that produced comparable ratings of drug effect (40 mg/70 kg cocaine versus 1.5 mg/70 kg nicotine), cocaine produced significantly greater good effects, whereas nicotine produced greater bad effects. All three cocaine doses and the intermediate and high nicotine doses were frequently categorized as producing effects similar to those of cocaine or amphetamine. The drug versus money measure showed that the highest cocaine dose was worth twice as much as the highest nicotine dose. Thus, intravenous cocaine and nicotine can be differentiated by their subjective and reinforcing effects.

The contribution of the β-turn sequence to the folding and stability of a peptide β-hairpin in water has been analysed from studies of a truncated peptide lacking one β-strand and hence the majority of the interstrand hydrophobic interactions; NMR analysis shows that the Asn-Gly type I′ β-turn conformation is significantly populated, suggesting that the intrinsic conformation preference of the turn sequence may play an important role in nucleating hairpin folding.

The copper catalysed oxidation of homocysteine has been studied by electron paramagnetic resonance (EPR) spectroscopy and spin trapping techniques to determine the nature of free radical species formed under varying experimental conditions. Three radicals; thiyl, alkyl and hydroxyl were detected with hydroxyl being predominant. A reaction mechanism is proposed involving Fenton chemistry. Inclusion of catalase to test for intermediate generation of hydrogen peroxide showed a marked reduction in amount of hydroxyl radical generated. In contrast, the addition of superoxide dismutase showed no significant effect on the level of hydroxyl radical formed. Enhanced radical formation was observed at higher levels of oxygen, an effect which has consequences for differential oxygen levels in arterial and venous systems. Implications are drawn for a higher incidence of atherosclerotic plaque formation in arteries versus veins.