The ASACUSA Micromegas Tracker: A cylindrical, bulk Micromegas detector for antimatter research.

The ASACUSA Micromegas Tracker (AMT; ASACUSA: Atomic Spectroscopy and Collisions Using Slow Antiprotons) was designed to be able to reconstruct antiproton-nucleon annihilation vertices in three dimensions. The goal of this device is to study antihydrogen formation processes in the ASACUSA cusp trap, which was designed to synthesise a spin-polarised antihydrogen beam for precise tests of Charge, Parity, and Time (CPT) symmetry invariance. This paper discusses the structure and technical details of an AMT detector built into such an environment, its data acquisition system and the first performance with cosmic rays.

Efficacy of atorvastatin after LDL-cholesterol-based dose selection in high risk dyslipidaemic patients: results of the target dose study.

BACKGROUND: Hypercholesterolaemia is one of the major risk factors for the development of coronary heart disease (CHD). European guidelines emphasize the importance of reducing low-density lipoprotein cholesterol (LDL-C) levels below 115 mg/dL (3.0 mmol/L) in patients with high CHD risk. OBJECTIVE: The present study evaluates whether selection of the atorvastatin starting dose based on baseline LDL-C levels and previous statin treatment status would result in an achievement of LDL-C targets without the need for up-titration. METHODS: A multicentre, prospective, open-label study conducted in Belgium. Patients were at high risk defined as either a history of CHD, another atherosclerotic disease, diabetes mellitus Type 2 or an estimated 10-year CHD risk > 20%. The primary endpoint was the proportion of patients achieving the LDL-C goal after 12 weeks of treatment. RESULTS: Overall, 96.4% of the 195 statin-naïve patients reached the LDL-C target after 12 weeks of treatment. The majority of the patients (95.4%) already reached LDL-C control at Week 6. Mean (SD) LDL-C levels decreased from 159 (25) mg/dL[(4.1 (0.6) mmol/L] to 86 (14) mg/dL [2.2 (0.4) mmol/L] after 12 weeks of treatment. Only 4.6% of the patients needed an up-titration at Week 6. CONCLUSIONS: Taken together, the results demonstrate that LDL-C based dose selection of atorvastatin is highly efficacious for rapid achievement of target LDL-C levels with a low need for up-titration. Application of this flexible first dosing strategy in general practice will, based on available evidence, increase adherence to atorvastatin treatment in patients with high CHD risk.

Interindividual differences of medial temporal lobe activation during encoding in an elderly population studied by fMRI.

Functional MRI (fMRI) is used to study medial temporal lobe (MTL) activation during encoding of new information into memory. In most studies, fMRI data of different subjects are averaged in standard coordinate space. However, interindividual differences in activation can be extensive, reflecting functional heterogeneity. Further, anatomical differences in brain structure cause additional variance and loss of registration accuracy. Such differences in structural and functional MTL characteristics may interfere with the efficiency of averaging data across subjects, and may become more significant with aging and dementia. The current study concerns the analysis of individual differences in MTL activation associated with episodic encoding.Twenty-nine healthy elderly men between 60 and 70 years old performed a simple face encoding task during fMRI scanning. Individual data were analyzed in native space, and compared to the group average in standard space (Talairach and Tournoux).MTL volumes between subjects varied between 6.34 and 11.27 cm(3), and had considerable variation when mapped to standard space. Eighteen of the 29 subjects showed MTL activity and activation patterns varied both in location and size (ranging from 0.11 to 1.78 cm(3)), with the strongest activation in the left posterior part of the MTL. In standard space, no region was significantly activated on a group level at a comparable alpha level. We conclude that while the majority of elderly subjects show MTL activation during episodic encoding of faces, there is considerable structural and functional variability between subjects. Group analysis in standard space may not be appropriate for studies of a complex structure such as the MTL, particularly not in aging and dementia.

Inflammatory markers in younger vs elderly normal volunteers and in patients with Alzheimer's disease.

BACKGROUND: Recently it has been reported that activation of the inflammatory response system (IRS) may play a role in the aging process and in the pathogenesis of the degenerative changes associated with Alzheimer's disease (SDAT). The aims of the present study were to examine the peripheral IRS in normal aging and in SDAT patients. METHODS: Serum zinc (Zn), total serum protein (TSP), albumin (Alb), SP electrophoresis, and serum interleukin-6 (IL-6) and the stimulated production of tumor necrosis factor-alpha (TNFalpha) were determined in younger versus elderly healthy subjects and in SDAT patients vs. age-matched, healthy volunteers. RESULTS: Serum Zn and Alb were significantly lower in elderly than in younger healthy volunteers and were significantly and inversely correlated with age. The production of TNFalpha was significantly higher in elderly than in younger healthy volunteers and was significantly and positively correlated with age. In SDAT patients, no significant changes in serum Zn or TNFalpha production could be found. Serum Alb was significantly lower and serum IL-6 and the alpha1 and alpha2 globulin fractions significantly higher in SDAT patients than in controls. CONCLUSIONS: Activation of the IRS appears to accompany the normal aging process, i.e. lower serum Zn and Alb and increased TNFalpha production, as well as SDAT, i.e. lower serum Alb and increased serum IL-6 and alpha1 and alpha2 globulin fractions. The findings suggest that not all indicators of IRS activation in SDAT are related to those of the normal ageing process.

[Fixation of nasogastric tubes in agitated and uncooperative patients]. / Fixation des sondes naso-gastriques chez les patients agités et peu compliants.

To prevent extubation, nasogastric tubes (NGT) were attached to a fine bore polyurethane tube, which loops loosely around the nasal septum. In a prospective study 180 cases were evaluated concerning the efficacy and possible complications related to this techniques. On average, a nasal septal loop (NSL) remained 20.1 +/- 1.3 days and a NGT 14 +/- 0.9 days. Complications were rare. In 45 of the cases NGT had to be replaced after self extubation and in 2.2% extubation presented more than twice. We think NSL is an easy and useful technique to secure NGT in non-cooperative and/or agitated patients for a relatively short term enteral nutrition or gastric decompression.

Thyrotoxic periodic paralysis, an unusual cause of hypokalemic periodic paralysis.

Over a two-year period two patients were admitted to the hospital with episodes of paralysis and hypokalemia. In the first patient, familial hypokalemic periodic paralysis was initially suspected. Only several months later was Graves' disease diagnosed and this diagnosis linked to thyrotoxic periodic paralysis. The second patient came to notice after treatment with thyreostatic drugs was stopped prematurely and paralysis together with hypokalemia developed. Thyrotoxic periodic paralysis, being rare outside Asia, closely mimics the clinical presentation of familial hypokalemic periodic paralysis. Mainly men in the third decade with a negative family history are affected. Graves' disease is the most common cause of hyperthyroidism. This disorder is not always clinically apparent since signs of hyperthyroidism may be easily missed. Therefore thyroid function tests are part of the diagnostic workup of hypokalemic periodic paralysis. Correction of thyroid function is essential to treatment. The pathophysiology is still controversial.

Securing nasogastric tubes in non-cooperative patients.

To prevent extubation, nasogastric tubes (NGT) were attached to a fine bore polyurethane tube, which loops loosely around the nasal septum. In a prospective study, 124 cases were evaluated for the efficiency and possible complications. On average, a Nasal Septal Loop (NSL) remained 21,2 +/- 1,8 days and a NGT 13,8 +/- 1,1 days. Complications were rare. In 16,9% of the cases NGT had to be replaced after self extubation and in 2.4% extubation occurred more than twice. We think NSL is an easy and useful technique for securing NGT in non-cooperative and/or agitated patients for relatively short term enteral nutrition or gastric decompression.

Role of endocardial endothelium in the positive inotropic effect of cholic acid in isolated myocardium.

In isolated feline right ventricular papillary muscles, with intact or damaged (exposure to dry air for 30 s) endocardium, the effects of cholic acid were studied. At 35 degrees C and a [Ca2+] of 1.25 mM, isometric twitches and the maximal unloaded velocity of shortening (Vmax) were registered. Endocardial endothelium (EE) and myocardial ultrastructure were evaluated on scanning and transmission electron microscopy. In muscles with intact EE, low concentrations of cholic acid (3 x 10(-9) to 3 x 10(-7) M) or short incubation (30 min) with 3 x 10(-8) M induced a mild positive inotropic response, manifested as an increased peak isometric twitch tension (TT) and shortened twitch duration, without changes in Vmax. This inotropic response was abolished by damaging the EE. It was also absent after the addition of propranolol to muscles with intact EE. Higher concentrations (3 x 10(-6) to 3 x 10(-4) M) or prolonged incubation at 3 x 10(-8) M caused extensive morphologic damage of the EE, without detectable impairment of subjacent myocardium. This was accompanied by a progressive decrease in the TT and further twitch abbreviation, without changes in Vmax, resembling twitches obtained from muscles with experimentally damaged EE. These observations suggest that cholic acid induces an EE-dependent and beta-receptor-mediated positive inotropic effect, while simultaneously causing damage to EE cells.

Morphological and functional changes during thyroid hyperplasia and involution in C3H mice: effects of iodine and 3,5,3'-triiodothyronine during involution.

Involution of thyroid hyperplasia was induced in mice by discontinuing a goitrogenic treatment (low iodine diet plus 0.25% propylthiouracil for 10 days) and returning either to a moderate iodine diet (MID; 1 microgram I/day) alone or associated with T3 administration (1 microgram/day) or to a high iodine diet (HID; 10 micrograms I/day) alone or associated with T3 treatment. Thyroid involution was studied by morphological, stereological, and biochemical methods after 2, 4, 6, and 8 days of involution. Age-paired, HID-fed animals were used as controls. When the involution was induced by MID, the glands resumed a normal morphological aspect. The synthesis and secretion of T3 were highly stimulated on day 2, but decreased thereafter. Plasma T4 levels reached a plateau at 50% of the control value from days 2-8. The administration of T3 together with MID accelerated the involution of hyperplasia and colloid accumulation in the follicular lumina. The synthesis and secretion of T3 and T4 remained lower than those in controls. When the involution was induced by HID, the thyroid weight remained higher than that in controls or in any involuting groups. The number of follicles and epithelial cells as well as the glandular thyroglobulin content were twice the control values. A Wolff-Chaikoff effect was evident on day 4, and hypothyroidism persisted. When HID was supplemented with T3 treatment, glandular weight and morphology were normal, but the Wolff-Chaikoff effect occurred earlier. In conclusion, the iodine dose given after a goitrogenic treatment must be carefully controlled; a high but physiological dose can have deleterious effects, whereas a small dose is beneficial. T3 prevents the deleterious effects of HID, but the thyroid enters a resting state.

[Sialic acid content of human thyroglobulins iodinated at different levels (author's transl)]. / Teneur en acide sialique de thyroglobulines humaines iodées à différents niveaux.

Sialic acid and iodine content were measured on 53 thyroglobulins from normal and pathological tissues. Sialic acid is significantly decreased in isolated cold nodules, and highly reduced in hot nodules and toxic adenomas. In these pathological situations, sialic acid defect could interfere with the iodination of the molecule.

Secretory activity of isolated thyroid adenomas.

The catabolic phase of thyroid secretion --thyroglubulin (Tg) uptake and hydrolysis, release of hormones--has been investigated in vitro, by incubating thyroid slices with 0.1% labelled Tg, in cases of isolated adenomas. Twenty-two specimens were examined: 11 cold follicular adenomas, 5 hot nodules from euthyroid patients, 2 untreated toxic adenomas, and 4 pretreated toxic adenomas. The results were compared with those obtained in 11 specimens of normal tissue. Tg pinocytosis (the amount of Tg taken up by the slices per mg of tissue) was severely impaired in all the non-toxic nodules, cold or hot, i.e., whatever the in vivo activity of the thyroid iodide pump. In toxic adenomas, every step of the catabolic hormonogenesis was activated: high pinocytotic activity, increased Tg hydrolysis, and the discharge of hormonal products; in pretreated cases, the whole process was slowed down. Enzymic activity of the acid hydrolases, beta-galactosidase and cathepsin, was elevated in all the nodules so far investigated, particularly in the toxic adenomas.

Defective thyroglobulin endocytosis and hydrolysis in thyroid cold nodules.

The catabolic phase of thyroid secretion has been studied by incubating thyroid slices with 0.1 % 125-I thyroglobulin (Tg) in the following cases: 11 follicular adenomas (FA), 8 hyerplastic nodules in multinodular glands (NM), 3 carcinomas (follicular or papillary, FC, PC) and normal (N) or micronodular tissue (M). Tg pinocytosis is severely impaired in all cold nodules (25 to 60 % reduction). In the follicular tumours (FA, FC), Tg hydrolysis is more affected than would be expected based only on reduced Tg endocytosis: the hydrolysis products remain in the phagolysosomes instead of being secreted. As far as the acid hydrolases are concerned these enzymatic activities are increased in nearly all nodules, in particular in follicular adenomas and carcinomas.