Comparison of selective media for isolation of Campylobacter jejuni/coli

A comparison of Skirrow's, Butzler's, Blaser's, Campy-BAP and Preston media for Campylobacter spp was made using human, animal and environmental specimens. Butzler's medium gave the lowest isolation rate and Preston medium, which was the most selective, the highest isolation rate. Enrichment culture using Preston enrichment broth gave a higher isolation rate than direct plating onto Preston medium.     

Effects of histamine antagonists on noradrenaline-stimulated blood flow and oxygen consumption of brown adipose tissue in the rat

The effects of histamine antagonists on noradrenaline-stimulated metabolic rate, tissue blood flow (estimated from the distribution of radiolabelled microspheres) and brown adipose tissue (BAT) oxygen extraction were studied in male anaesthetised rats. Injection of cimetidine (H2-receptor antagonist), reduced the noradrenaline-stimulation of metabolic rate and the increase in blood flow to BAT, but did not affect blood flow to white adipose tissue, skin, leg muscle, kidney, brain, or testes. Following noradrenaline, in vivo oxygen consumption of BAT, estimated from blood flow and oxygen extraction was depressed to 31% of control values by treatment with cimetidine, blood pressure was unaffected. Injection of the histamine (H1-receptor) antagonist, mepyramine, did not affect tissue blood flow or metabolic rate. In conscious animals, cimetidine did not affect resting oxygen consumption, but depressed the thermogenic responses to noradrenaline. These data suggest that the stimulation of BAT blood flow and thermogenesis by noradrenaline may be mediated in part by histamine acting on an H2-type receptor.     

Abnormalities in motor cortical plasticity differentiate manifesting and nonmanifesting DYT1 carriers.

A mutation in the DYT1 gene causes dominantly inherited childhood-onset primary dystonia, but intriguingly, only 30 to 40% of those who carry the mutation ever develop symptoms. We have used the unique model provided by this group of patients to investigate the hypothesis that abnormalities in brain plasticity underlie the pathophysiology of primary dystonia. We recruited 8 DYT1 gene carriers with dystonia, 6 DYT1 gene carriers without dystonia, 6 patients with sporadic primary dystonia (torticollis), and 10 healthy control subjects. Groups were age-matched. We compared the effect in these groups of subjects of repetitive transcranial magnetic stimulation (rTMS) delivered to the motor cortex, by assessing changes in corticospinal excitability following rTMS. rTMS was given in the form of theta burst stimulation (TBS) using the inhibitory protocol "cTBS" (total of 300 pulses in 50-Hz bursts given every 5Hz). DYT1 gene carriers with dystonia and subjects with torticollis had a significantly prolonged response to rTMS in comparison with healthy subjects. In contrast, DYT1 gene carriers without dystonia had no significant response to rTMS. These data demonstrate an excessive response to an experimental "plasticity probing protocol" in subjects with dystonia, but a lack of response in genetically susceptible individuals who have not developed dystonia. These preliminary data suggest that the propensity to undergo plastic change may affect the development of symptoms in genetically susceptible individuals and that this may be an important mechanism in the pathogenesis of primary dystonia in general.     

Central actions of CRF on thermogenesis are mediated by pro-opiomelanocortin products

Corticotrophin-releasing factor (CRF) causes central activation of thermogenesis. The aim of this study was to investigate whether this action is mediated by ACTH or other peptides derived from the ACTH precursor pro-opiomelanocortin (POMC) within the CNS. Central (intracerebroventricular) injection of rat CRF caused dose-dependent increases in resting oxygen consumption (VO2) in conscious rats (maximal 26 +/- 5% at 2 nmol CRF). These responses were significantly attenuated by pretreatment (i.c.v.) with either a monoclonal antibody raised to gamma 1MSH or with naloxone which antagonises beta-endorphin (beta-EP) actions. The increases were not affected by pretreatment with monoclonal antibodies to ACTH or the N-terminal of POMC. Central injections of gamma 1-melanocyte-stimulating hormone (MSH) or beta-EP caused dose-dependent increases in VO2 (maximal at 0.5-1.5 pmol) and these were markedly inhibited by pretreatment with the anti-gamma 1-MSH antibody or naloxone respectively. Injection of ACTH or alpha MSH did not significantly affect VO2 at doses up to 2 nmol. These data indicate that the central actions of CRF on thermogenesis may be mediated, at least in part, by release of gamma MSH and/or beta-EP.     

Physiological analysis of simple rapid movements in patients with cerebellar deficits.

Patients with cerebellar deficits made elbow flexion movements as rapidly as possible for three different angular distances. Electromyographic activity of biceps and triceps and the kinematics of the movements were analysed. Results were compared with those of normal subjects making both rapid and slow movements. In the patients, the first agonist burst of the biceps was frequently prolonged regardless of the distance or speed of the movement. The most striking kinematic abnormality was prolonged acceleration time. The pattern of acceleration time exceeding deceleration time was common in patients but uncommon in normal subjects. The best kinematic correlate of the duration of the first agonist burst was acceleration time. Altered production of appropriate acceleration may therefore be an important abnormality in cerebellar dysfunction for attempted rapid voluntary movements.     

A systematic comparison of the quality and volume of published data available on novel risk factors for stroke versus coronary heart disease

BACKGROUND: To identify new treatments to prevent stroke, it is important that we have reliable data on potential novel risk factors. METHODS: We studied seven novel vascular risk factors [apo-lipoprotein (b), C-reactive protein, Chlamydia pneumoniae, fibrin-D dimer, fibrinogen, Helicobacter pylori and lipoprotein (a)] and compared the amount of published data on their relations with ischaemic stroke versus acute coronary events by systematic review of all studies published up to 2003. RESULTS: From a total of 22,875 abstracts reviewed, 266 eligible studies were identified (167 case-control studies and 99 cohort studies). Two hundred and eleven (79%) studies included coronary events as an outcome for the purpose of a risk factor analysis. In 186 (70%) studies, coronary events were the only outcome that was analysed. Only 73 (27%) studies included stroke or TIA as an outcome event, and only 45 studies (17%) reported risk factor analyses for ischaemic stroke separately. These results were qualitatively consistent across the risk factors studied and the relative lack of data on risk factors for stroke was even greater in prospective cohort studies. CONCLUSION: Data on novel risk factors for stroke are lacking compared with the equivalent data for acute coronary events, and there are very few data on specific subtypes of ischaemic stroke.