Modulation of feeding by chronic rAAV expression of a relaxin-3 peptide agonist in rat hypothalamus.

Relaxin-3 is a neuropeptide that is abundantly expressed by discrete brainstem neuron populations that broadly innervate forebrain areas rich in the relaxin-3 G-protein-coupled-receptor, RXFP3. Acute and subchronic central administration of synthetic relaxin-3 or an RXFP3-selective agonist peptide, R3/I5, increase feeding and body weight in rats. Intrahypothalamic injection of relaxin-3 also increases feeding. In this study, we developed a recombinant adeno-associated virus 1/2 (rAAV1/2) vector that drives expression and constitutive secretion of bioactive R3/I5 and assessed the effect of intrahypothalamic injections on daily food intake and body weight gain in adult male rats over 8 weeks. In vitro testing revealed that the vector rAAV1/2-fibronectin (FIB)-R3/I5 directs the constitutive secretion of bioactive R3/I5 peptide. Bilateral injection of rAAV1/2-FIB-R3/I5 vector into the paraventricular nucleus produced an increase in daily food intake and body weight gain (P<0.01, ~23%, respectively), relative to control treatment. In a separate cohort of rats, quantitative polymerase chain reaction analysis of hypothalamic mRNA revealed strong expression of R3/I5 transgene at 3 months post-rAAV1/2-FIB-R3/I5 infusion. Levels of mRNA transcripts for the relaxin-3 receptor RXFP3, the hypothalamic 'feeding' peptides neuropeptide Y, AgRP and POMC, and the reproductive hormone, GnRH, were all similar to control, whereas vasopressin and oxytocin (OT) mRNA levels were reduced by ~25% (P=0.051) and ~50% (P<0.005), respectively, in rAAV1/2-FIB-R3/I5-treated rats (at 12 weeks, n=9/8 rats per group). These data demonstrate for the first time that R3/I5 is effective in modulating feeding in the rat by chronic hypothalamic RXFP3 activation and suggest a potential underlying mechanism involving altered OT signalling. Importantly, there was no desensitization of the feeding response over the treatment period and no apparent deleterious health effects, indicating that targeting the relaxin-3-RXFP3 system may be an effective long-term therapy for eating disorders.

A biofilm model for engineering design.

A biofilm model is presented for process engineering purposes--wastewater treatment plant design, upgrade and optimisation. The model belongs in the 1D dynamic layered biofilm model category, with modifications that allow it to be used with one parameter set for a large range of process situations. The biofilm model is integrated with a general activated sludge/anaerobic digestion model combined with a chemical equilibrium, precipitation and pH module. This allows the model to simulate the complex interactions that occur in the aerobic, anoxic and anaerobic layers of the biofilm. The model has been tested and is shown to match a variety of design guidelines, as well as experimental results from batch testing and full-scale plant operation. Both moving bed bioreactors (MBBR) and integrated fixed film activated sludge (IFAS) systems were simulated using the same model and parameter set. A new steady-state solver generates fast solutions and allows interactive design work with the complex model.

Gene expression and genotyping studies implicate the interleukin 7 receptor in the pathogenesis of primary progressive multiple sclerosis.

Multiple sclerosis (MS) is an enigmatic disease of the central nervous system resulting in sclerotic plaques with the pathological hallmarks of demyelination and axonal damage, which can be directly or indirectly orchestrated by cells from the peripheral circulation. The majority of patients with MS follow a relapsing-remitting course in the early stages of the disease (RRMS) but most ultimately enter a secondary progressive phase (SPMS). About 10% of patients follow a primary progressive course from the onset (PPMS). We measured gene expression in whole blood of people with and without chronic progressive MS (CPMS), PPMS and SPMS, to discover genes which may be differentially expressed in peripheral blood in active disease, and so identify pathologically significant genes and pathways; and we investigated genetic differences in the promoters of dysregulated genes encoded in genomic regions associated with MS. If SPMS and PPMS were independently compared to the controls, there was little overlap in the set of most dysregulated genes. Ribosomal protein genes, whose expression is usually associated with cell proliferation and activation, were dramatically over-represented in the set of most down-regulated genes in PPMS compared to SPMS (P < 10(-4), chi(2)). The T cell proliferation gene IL7R (CD127) was also underexpressed in PPMS, but was up-regulated in SPMS compared to the controls. One interleukin 7 receptor (IL7R) promoter single nucleotide polymorphism (SNP), -504 C, was undertransmitted in PPMS trios (P = 0.05, TDT), and carriers of this allele were under-represented in PPMS cases from two independent patient cohorts (combined P = 0.006, FE). The four known IL7R promoter haplotypes were shown to have similar expression levels in healthy controls, but not in CPMS (P < 0.01, t test). These data support the hypothesis that PPMS has significant pathogenetic differences from SPMS, and that IL7R may be a useful therapeutic target in PPMS.

Subtle learning and memory impairment in an idiopathic rat model of Alzheimer's disease utilizing cholinergic depletions and ß-amyloid.

Alzheimer's disease (AD) is a disease of complex etiology, involving multiple risk factors. When these risk factors are presented concomitantly, cognition and brain pathology are more severely compromised than if those risk factors were presented in isolation. Reduced cholinergic tone and elevated amyloid-beta (Aß) load are pathological hallmarks of AD. The present study sought to investigate brain pathology and alterations in learning and memory when these two factors were presented together in rats. Rats received either sham surgeries, cholinergic depletions of the medial septum, intracerebroventricular Aß25-35 injections, or both cholinergic depletion and Aß25-35 injections (Aß+ACh group). The Aß+ACh rats were unimpaired in a striatal dependent visual discrimination task, but had impaired acquisition in the standard version of the Morris water task. However, these rats displayed normal Morris water task retention and no impairment in acquisition of a novel platform location during a single massed training session. Aß+ACh rats did not have exacerbated brain pathology as indicated by activated astroglia, activated microglia, or accumulation of Aß. These data suggest that cholinergic depletions and Aß injections elicit subtle cognitive deficits when behavioural testing is conducted shortly after the presentation of these factors. These factors might have altered hippocampal synaptic plasticity and thus resemble early AD pathology.

Nitrification parameter measurement for plant design: experience and experimental issues with new methods.

Nitrification kinetics are important for process design, optimization, and capacity rating of activated sludge wastewater treatment plants. A Water Environment Research Foundation (WERF) project on Methods for Wastewater Characterization in Activated Sludge Modeling (WERF, 2003) focused significantly on the development of procedures for measuring the nitrifier maximum specific growth rate, micro(AUT). In addition, the importance of (and lack of data for) the nitrifier decay rate, b(AUT), was identified. This paper describes three bench-scale methods for measuring micro(AUT): the Low F/M SBR, Washout and High F/M methods. During the WERF project, the importance of pH and temperature control was investigated briefly; this paper summarizes further experimental work performed to address these issues. A summary of micro(AUT) measurements in a number of locations and using the different measurement techniques is provided.

Importance and measurement of decay rate when assessing nitrification kinetics.

Nitrification kinetics are important for process design, optimization and capacity rating of activated sludge wastewater treatment plants. Assessment of nitrification behaviour historically has focused on measuring the nitrifier maximum specific growth rate, micro(AUT). Very little attention has been directed at the of nitrifier organism rate has been assumed negligible. However, incorrect assessment of decay rate leads to errors in the micro(AUT) estimate; the magnitude of the error depends on the micro(AUT) measurement method employed. This paper illustrates why decay rate is important when measuring micro(AUT), and that the decay rate is significant. The paper also explains why measurement methods for nitrifier decay may have underestimated the decay rate. Results from an experiment incorporating improvements to previously suggested methods and data analysis are presented.

Strain and sex differences in brain and behaviour of adult rats: Learning and memory, anxiety and volumetric estimates.

Alterations in behaviour can arise through a number of factors, including strain and sex. Here, we explored strain and sex differences between Long-Evans (LER) and Wistar (WR) male and female rats that had been trained in a myriad of behavioural tasks. Tests included those assessing motor learning (skilled reaching task), spatial learning and memory (Morris water task), contextual learning (discriminative fear-conditioning to context) and anxiety behaviour (elevated plus maze). Following behavioural assessment, associated brain areas were examined for volumetric differences, including the hippocampus and its subregions, prefrontal cortex areas and the amygdala. LER and WR differed in their rates of performance in the skilled reaching task throughout the training period. Overall, LER outperformed WR in tasks related to contextual and spatial learning, although this was not accompanied by larger volumes of associated brain areas. Males outperformed females in spatial learning, and females outperformed males in the contextual fear-conditioning task and had an associated larger amygdalar volume, although these sexual dimorphisms were only observed within the LER strain. Overall, this study highlights differences between these two rat strains as well as highlights that larger volumetric estimates of brain areas do not always confer improved function of associated behaviours.

Part II: Strain- and sex-specific effects of adolescent exposure to THC on adult brain and behaviour: Variants of learning, anxiety and volumetric estimates.

Marijuana is one of the most highly used psychoactive substances in the world, and its use typically begins during adolescence, a period of substantial brain development. Females across species appear to be more susceptible to the long-term consequences of marijuana use. Despite the identification of inherent differences between rat strains including measures of anatomy, genetics and behaviour, no studies to our knowledge have examined the long-term consequences of adolescent exposure to marijuana or its main psychoactive component, Δ(9)-tetrahydrocannabinol (THC), in males and females of two widely used rat strains: Long-Evans hooded (LER) and Wistar (WR) rats. THC was administered for 14 consecutive days following puberty onset, and once they reached adulthood, changes in behaviour and in the volume of associated brain areas were quantified. Rats were assessed in behavioural tests of motor, spatial and contextual learning, and anxiety. Some tasks showed effects of injection, since handled and vehicle groups were included as controls. Performance on all tasks, except motor learning, and the volume of associated brain areas were altered with injection or THC administration, although these effects varied by strain and sex group. Finally, analysis revealed treatment-specific correlations between performance and brain volumes. This study is the first of its kind to directly compare males and females of two rat strains for the long-term consequences of adolescent THC exposure. It highlights the importance of considering strain and identifies certain rat strains as susceptible or resilient to the effects of THC.

A completely absorbed oral preparation of digoxin.

Digoxin absorption was studied in healthy volunteers by determination of peak plasma concentrations, areas under plasma concentration curves, and urinary excretion after single-dose administration. By comparison with an aqueous solution, increased rate and extent of absorption occurred from experimental soft gelatin formulations of digoxin in solution. Enhanced bioavailability of the capsules was not affected by altered volume of contained solvent. Digoxin was considerably better absorbed from capsules than from tablets of moderately high dissolution rate. Mean percentage intestinal absorption was 75% from tablet and 97% from capsules. Reduced between-subject variability accompanied the enhanced absorption from capsules.

Effect of a standard breakfast on digoxin absorption in normal subjects.

The influence of food on absorption of digoxin was studied in 6 healthy volunteers who received 1.0 mg digoxin as 4 tablets of Lanoxin either after an overnight fast, immediately after a standard breakfast, or 90 min after a standard breakfast. There was no significant difference between the three regimens in terms of area under the plasma concentration-time curve for 79 hr or in the 10-day cumulative urinary excretion. The mean peak plasma concentration was higher (p less than 0.05) when digoxin was given fasting (4.2 +/- 0.46 ng/ml) than immediately after food (2.8 +/- 0.24 ng/ml). The mean peak plasma concentration when digoxin was administered 90 min after food (3.3 +/- 0.30 ng/ml) was intermediate but not significantly different from either of the other mean peak concentrations. The results demonstrate that ingestion of food decreases rate but not extent of absorption of concurrently administered digoxin.

An intergenerational program for persons with dementia using Montessori methods.

An intergenerational program bringing together older adults with dementia and preschool children in one-on-one interactions is described. Montessori activities, which have strong ties to physical and occupational therapy, as well as to theories of developmental and cognitive psychology, are used as the context for these interactions. Our experience indicates that older adults with dementia can still serve as effective mentors and teachers to children in an appropriately structured setting.

Tackling obesity in men -- preliminary evaluation of men-only groups within a commercial slimming organization.

BACKGROUND: Over Slimming World's 36-year history men have always made up a small percentage of the slimming organization's membership. Past company research suggested that men would feel more comfortable in men-only groups rather than mixed. In 2002, Slimming World set a target to raise the awareness among men about the dangers of being overweight and made practical weight-management solutions more accessible through a national network of men's groups. AIM: To evaluate men's weight loss within these 'men-only' groups. METHODS: Data analysed included those men having attended a group for at least 8 weeks. RESULTS: At the point of data collection average BMI had decreased from 35.9 to 32.5 kg m(-2). At least 5% weight loss was achieved in 90% of the sample. In those who had been members for 24 weeks 69% achieved a 10% weight loss. Shift working did not affect weight loss success. CONCLUSION: This data shows that overweight and obese men attending Slimming World are successful at losing weight in this environment and can achieve recommended health-related weight loss targets. There should be a move to get away from the mis-perception that slimming groups are only for women and raise awareness of the commercial option to men.

Maximal intestinal absorption of digoxin, and its relation to steady state plasma concentration.

In a group of 8 volunteers, peak plasma digoxin concentrations and areas under 80-hour plasma concentration curves were significantly greater after 1 mg digoxin in paediatric elixir than after 4 0,25 mg tablets. Mean cumulative urinary excretion of digoxin over 12 days was 46.4 per cent after tablets, 53.6 per cent after elixir, and 70.8 per cent after intravenous injection. Mean percentage absorption was estimated to be 63 per cent from tablets and 75 per cent from elixir, but considerable between-subject variation was noted. Individual estimates of percentage absorption were significantly correlated with plasma concentrations in the steady state. Computer programmes to relate steady state plasma concentration to oral digoxin dosage take no account of absorptive capacity, are limited to gross approximations, and cannot replace determination of plasma concentration to assess the degree of digitalization.

A comparison of triprolidine and clemastine on histamine antagonism and performance tests in man: implications for the mechanism of drug induced drowsiness.

The effects of triprolidine hydrochloride 1.25, 2.5 and 5 mg, clemastine 1 and 2 mg and lactose dummy administered orally, in a balanced order, at weekly intervals to 12 healthy volunteers, on the flare and weal responses to intradermal histamine injection, and also on both subjective effects and objective psychomotor tests were examined. The histamine response was significantly larger at 09.00 h falling through the day but increasing by late afternoon. Triprolidine produced a dose-related antagonism of both flare and weal response maximal at 3 h and wearing off after the lower doses at 8 h. Clemastine by contrast produced poor antagonism of histamine at 3 h but a marked effect at 5.5 and 8 h. Auditory vigilance was significantly (p less than 0.05) impaired by all doses of triprolidine 1 to 2 h after administration, but no change followed clemastine at this time. When tested 6 to 7 h after administration significant impairment followed both doses of clemastine but only the 5 mg dose of triprolidine. Both drugs prolonged reaction time in a dose-related manner at 2.5 and 5.0 h but the effects had worn off at 7 h. Digit symbol substitution was impaired by the top doses of both antihistamines but short term memory was unaffected. Subjective effects measured using analogue lines reflected the effects in the vigilance test, in that drowsiness and mental impairment were noted early after triprolidine, while clemastine produced maximal effects at 5 h. Subjects were ranked in order of magnitude of inhibition of both flare and weal, and impairment of vigilance, prolongation of reaction time and subjective drowsiness score. There was no indication of a significant correlation, using Spearman's test, between antagonism of histamine and effects on the central nervous system.

Effects on the human central nervous system of two isomers of ephedrine and triprolidine, and their interaction.

1 D(-)ephedrine is four times as potent as L(+)pseudoephedrine in producing both tachycardia and a rise in systolic blood pressure. No changes in diastolic blood pressure occurred in 12 subjects with doses of up to D(-)ephedrine (50 mg) and L(+)pseudoephedrine (180 mg). 2 Significant evidence of stimulation of the central nervous system occurred only after D(-)ephedrine in that tapping rates were increased and subjects could reliably detect that they had received an active drug. While mean performance rates in an auditory vigilance test were higher following both ephedrine isomers these changes were not significant. 3 Impairment of both tapping rates and auditory vigilance occurred following triprolidine in another group of 12 subjects. The effect was generally related to dose of antihistamine given and lasted up to 7.25 hours. Subjective effects were reliably recognized by subjects following all treatments containing triprolidine (2.5 mg or more) for up to 4.75 hours. Using analogue lines for self rating the subjective effects following triprolidine indicated both mental and physical impairment differing significantly from scores after lactose and L(+)pseudoephedrine (60 mg). 4 Combination of triprolidine (2.5 mg) and L(+)pseudoephedrine (60 mg) produced effects similar to triprolidine alone on both subjective measures and the auditory vigilance test. It is suggested that these objective tests and subjective scales could be used to measure effects on the central nervous system produced by antihistamines together with similar drugs, and their interaction with other compounds administered concurrently.

A study of the pharmacokinetic interaction between lamivudine and alpha interferon.

OBJECTIVE: This study was designed to investigate any possible pharmacokinetic interaction between lamivudine and alpha interferon as potential candidates for combination therapy for the treatment of hepatitis B virus (HBV). METHODS: Nineteen healthy male, Caucasian volunteers, aged 20-41 years and weighing 60.5-83.5 kg completed this open, non-randomised study. They each received a single, abdominal, deep s.c. injection of 10 mIU alpha interferon on day 1, followed by a wash-out period of at least 1 week. Subjects then began a 7-day course of lamivudine (100 mg) followed by a further 10-mIU alpha-interferon injection directly after oral lamivudine dosing. Blood and urine samples were taken pre- and post-dose for alpha-interferon and/or lamivudine assay. RESULTS: Lamivudine was safe and well tolerated in all subjects. No adverse events were reported in subjects on lamivudine, whereas 106 adverse events considered attributable to alpha interferon were recorded. Statistical analysis of pharmacokinetic parameters indicated no significant effect of lamivudine on alpha-interferon pharmacokinetics. There was a small statistically significant reduction (approximately 10%) in the area under the lamivudine concentration time curve on co-administration with alpha interferon and a concomitant increase in clearance, which is not considered clinically relevant. CONCLUSIONS: Alpha interferon and lamivudine can be co-administered with no requirement for dose modification, as there was no clinically significant difference in the pharmacokinetics of either drug.

A comparison of triprolidine and cyclizine on histamine (H1) antagonism, subjective effects and performance tests in man.

1 The effects of triprolidine and cyclizine on the histamine skin response, performance tests and subjective effects were examined in a controlled, double-blind study in eight healthy volunteers. 2 Triprolidine was considerably more potent that cyclizine in inhibiting the skin response to histamine. Significant inhibition of flare size occurred at 1, 2 an 4 h after triprolidine 2.5 mg. A smaller but significant reduction occurred at 2 and 4 h after cyclizine 100 mg but not after the 50 mg dose. 3 Cyclizine 100 mg produced a significant increase in reaction time at 4.5 h compared with lactose. Smaller though non significant increases followed triprolidine and cyclizine 50 mg. 4 Subjective effects were seen only after cyclizine 100 mg when subjects were significantly more drowsy, feeble, muzzy, lethargic and dreamy than after lactose dummy. No significant changes followed triprolidine 2.5 mg or cyclizine 50 mg. 5 It was concluded that while cyclizine has antihistamine properties, these are weak compared with triprolidine, and are not seen with doses sufficiently low to avoid central nervous system impairment.

The influence of digoxin particle size on absorption of digoxin and the effect of propantheline and metoclopramide.

1 The influence of particle size on absorption of digoxin was studied in ten healthy volunteers who received 0.5 mg digoxin as two standard Lanoxin tablets, or tablets containing micronized digoxin or large particle size digoxin. Tablets were given 30 min after 15 mg propantheline, 10 mg metoclopramine or a placebo tablet, and following an overnight fast. 2 The overall mean cumulative 4 day urinary excretion of digoxin was significantly lower (P less than 0.01) after large particle size digoxin than after standard or micronized digoxin. Mean cumulative urinary excretion following large particle size digoxin was reduced when administered after metoclopramide and increased after propantheline, the difference between these two treatments being significant (P less than 0.05). There was a significantly lower (P less than 0.05) overall mean cumulative excretion following standard by comparison with micronized digoxin. However, by comparison with placebo, neither metoclopramide nor propantheline significantly altered mean cumulative excretion after standard or micronized digoxin. Propantheline and metoclopramide affect absorption of digoxin from formulations of large particle size and slow dissolution rate only.

Drowsiness, impaired performance and tricyclic antidepressants drugs.

1. The effects of amitriptyline, protriptyline, protriptyline, and a chemically related potential antidepressant, BW247, on performance tests and subjective ratings were studied. 2. Two groups of twelve healthy subjects received drugs and lactose dummy in identical capsules at weekly intervals according to a balanced design, under double-blind conditions, and with standarized tests and environment. 3. Amitriptyline produced the most marked effects, with significant (P less than 0.05) impairment in auditory vigilance after 6.25 mg. Auditory reaction time, tapping rate, arithmetic, and digit symbol substitutions were impaired by amitriptyline 12.5 and 25 mg and all doses produced increased ratings of mental sedation. The effects began 1.5 h after drug and lasted approximately 5 h. 4. Nortriptyline produced fewer effects which were later in onset. Tapping at 1.8 h and auditory vigilance at 3.5 to 4.5 h were impaired by nortriptyline 25 mg whereas reaction time was prolonged by both doses at 5 h. No change in rating of mental sedation occurred. 5. No significant change in performance or subjective ratings followed protriptyline 10 mg or BW247, 12.5 and 25 mg. 6. The findings are discussed in relation to the presence of secondary and tertiary amines on the side chain of the compounds, and their relative abilities to block neuronal uptake of noradrenaline and 5-hydroxytryptamine.

The effects of low doses of amylobarbitone sodium and diazepam on human performance.

The effects of diazepam (2.5 and 5 mg) and amylobarbitone sodium (50 and 100 mg) on performance and subjective effects were assessed in a group of twelve healthy subjects under standardised conditions. Treatments were administered orally at weekly intervals according to a balanced design and under double-blind conditions. The tests of performance most sensitive to drug effects in these healthy subjects were either prolonged and monotonous and gave the subject no feedback on performance, or required short term memory for efficient execution. Auditory vigilance was significantly impaired (P less than 0.05) between 45 min and 1 h 45 min after all drug treatments except amylobarbitone sodium (100 mg), compared with performance after lactose. At the same time false reports were significantly increased after amylobarbitone sodium (100 mg) compared with all other active drugs but not with lactose. These effects had disappeared 4-5 h post drug. Short term memory was impaired 1h 45 min after all treatments and impairment was dose related. No significant effects occurred 5h after treatment. Simple auditory reaction time was prolonged 2 h after the highest doses of amylobarbitone sodium and diazpam, and by amylobarbitone sodium (50 mg) 5 h 15 min after treatment. At this time the effects of diazepam had worn off. Digit symbol substitution was impaired by amylobarbitone sodium (50 and 100 mg), and diazepam (5 mg) after 2 h 45 minutes. No significant changes in visual search or tapping occurred after active drugs compared with lactose. Subjective ratings indicated both mental and motor impairment 2 h 45 min after all active preparations compared with scores after lactose though significant changes followed diazepam (2.5 mg) infrequently. Both correct detections and false reports in auditory vigilance tended to fall over the 6 separate days of testing, indicating an increase in caution. Visual search, short term memory, tapping and digit symbol substitution significantly improved with time, but there was no change in reaction time. From the limited information obtained by sampling blood at 3 and 6 h, no relationship between change in performance and plasma level was found in these subjects.