Gadolinium Enhanced MR Coronary Vessel Wall Imaging at 3.0 Tesla.

Purpose. We evaluated the influence of the time between low-dose gadolinium (Gd) contrast administration and coronary vessel wall enhancement (LGE) detected by 3T magnetic resonance imaging (MRI) in healthy subjects and patients with coronary artery disease (CAD). Materials and Methods. Four healthy subjects (4 men, mean age 29 ± 3 years and eleven CAD patients (6 women, mean age 61 ± 10 years) were studied on a commercial 3.0 Tesla (T) whole-body MR imaging system (Achieva 3.0 T; Philips, Best, The Netherlands). T1-weighted inversion-recovery coronary magnetic resonance imaging (MRI) was repeated up to 75 minutes after administration of low-dose Gadolinium (Gd) (0.1 mmol/kg Gd-DTPA). Results. LGE was seen in none of the healthy subjects, however in all of the CAD patients. In CAD patients, fifty-six of 62 (90.3%) segments showed LGE of the coronary artery vessel wall at time-interval 1 after contrast. At time-interval 2, 34 of 42 (81.0%) and at time-interval 3, 29 of 39 evaluable segments (74.4%) were enhanced. Conclusion. In this work, we demonstrate LGE of the coronary artery vessel wall using 3.0 T MRI after a single, low-dose Gd contrast injection in CAD patients but not in healthy subjects. In the majority of the evaluated coronary segments in CAD patients, LGE of the coronary vessel wall was already detectable 30-45 minutes after administration of the contrast agent.

Conclusions on the measurement of arterial wall thickness: anatomic, physiologic and methodologic considerations

AIM: To discuss the use of new ultrasonic techniques that make it possible to visualize elastic (carotid) and muscular (radial) capacitance arteries non-invasively. RESULTS OF DATA REVIEW: Measurements of carotid wall thickness and the detection of atheromas are related to arterial pressure, to other risk factors and to the risk of subsequent complications. The use of high-frequency ultrasound (7.5-10 MHz), measurements of far wall thicknesses in areas free of atheromas at end-diastole (by ECG gating or pressure waveform recording) and descriptions of the size and characteristics of atherosclerotic plaques allow a non-invasive assessment of vascular hypertrophy and atherosclerosis in hypertensive patients. CONCLUSIONS: Careful attention to methodologic and physiologic factors is needed to provide accurate information about the anatomy of the dynamically pulsating arterial tree.

Active screening for pulmonary tuberculosis by chest x-ray among immigrants at the Swiss border

Summary : Aim: To assess the number of immigrants with pulmonary tuberculosis detected by chest x-ray screening at the Swiss border. Method: All adult immigrants entering Switzerland in 2004 were screened by chest x-ray (CXR). The number of radiological abnormalities suggestive of pulmonary tuberculosis, and the proportion requiring treatment for tuberculosis, were assessed retrospectively. The frequency of symptoms among immigrants with documented TB was compared with a sample of immigrants with a normal CXR. Results: Among 8995 immigrants, 8240 had a normal CXR, 630 had some abnormality not suggestive of active TB and 125 (1.4%) had a CXR suggestive of pulmonary TB. A final diagnosis of tuberculosis requiring treatment was made in SO (1 l with positive smear and culture, 16 with positive culture and 23 with negative culture), 57 had fibrotic lesions and 18 had another disease or a normal x-ray on control. The prevalence of symptoms did not differ between 27 immigrants with documented TB (smear+/culture+: 82%, smear-/ culture+: 75%), and 23 with smear-/culturetuberculosis (91%), but lower in 57 immigrants with fibrotic lesions (60%). Cough was more frequent among the 27 immigrants with documented TB (70%) than among 198 smokers without TB (37%) and among 229 non-smokers without TB (15%) Conclusions: Only 22% (27/125) of immigrants with CXR abnormalities suggestive of pulrnonary tuberculosis were documented by smear and/or culture and 40% (50/125) needed antituberculous treatment. 2/11 smear-positive immigrants would not have been detected by a questionnaire on symptoms. Rapport de synthèse : Le but de l'étude est d'évaluer le rendement du dépistage radiologique de la tuberculose pulmonaire chez les immigrés à l'entrée en Suisse. Méthode: parmi les immigrés adultes entrés en Suisse en 2004, qui ont tous passé un contrôle radiologique, le nombre de porteurs de clichés thoraciques suspects de tuberculose et la proportion de cas chez lesquels un traitement antituberculeux a été prescrit ont été évalués rétrospectivement. La fréquence des symptômes chez les immigrés atteints de tuberculose a été comparée à celle d'un groupe contrôle sans tuberculose. Résultats: parmi 8995 immigrés, 8240 avaient un cliché thoracique normal, 630 étaient porteurs d'une anomalie non suspecte de tuberculose active et 125 (1.4%) montraient des signes radiologiques suspects de tuberculose. Un diagnostic final de tuberculose nécessitant un traitement a été posé dans 50 cas (11 cas à frottis et culture positifs, 16 cas à culture positive, 23 cas à culture négative), 57 présentaient des lésions cicatricielles compatibles avec une ancienne tuberculose et 18 avaient une autre affection pulmonaire ou un cliché normal au contrôle. La prévalence des plaintes n'était pas différente entre les 27 immigrés porteurs d'une tuberculose documentée (frottis+ /culture+: 82%, frottis-/culture+ : 75%) et les 23 immigrés atteints d'une tuberculose non documentée (frottis-/culture-: 91%), mais elle était plus élevée que chez les 57 immigrés porteurs de lésions cicatricielles (59%). La toux était plus fréquente chez les 27 tuberculeux documentés (70%) que chez 198 fumeurs sans tuberculose (37%) et chez 229 non fumeurs sans tuberculose (15%). Conclusions: seuls 22% (27/125) des immigrés dont le cliché thoracique est suspect de tuberculose sont porteurs d'une tuberculose documentée par examen direct ou culture et 40% (50/125) nécessitent un traitement antituberculeux. Deux immigrants sur les 11 cas frottis positifs n'auraient pas été dépistés par un questionnaire.

Effect of testosterone on immunocompetence, parasite load, and metabolism in the common wall lizard (Podarcis muralis)

Testosterone can benefit individual fitness by increasing ornament colour, aggressiveness, and sperm quality, but it can also impose both metabolic and immunological costs. However, evidence that testosterone causes immuno suppression in freely living populations is scant. We studied the effects of testosterone on one component of the immune system (i.e., the cell-mediated response to phytohaemagglutinin), parasite load, and metabolic rate in the common wall lizard, Podarcis muralis (Laurenti, 1768). For analyses of immunocompetence and parasitism, male lizards were implanted at the end of the breeding season with either empty or testosterone implants and were returned to their site of capture for 5-6 weeks before recapture. For analyses of the effects of testosterone on metabolic rate, male lizards were captured and implanted before hibernation and were held in the laboratory for 1 week prior to calorimetry. Experimental treatment with testosterone decreased the cell-mediated response to the T-cell mitogen phytohemagglutinin and increased mean metabolic rate. No effects of testosterone on the number of ectoparasites, hemoparasites, and resting metabolic rate could be detected. These results are discussed in the framework of the immunocompetence handicap hypothesis and the immuno-redistribution process hypothesis. [Authors]

tagO is involved in the synthesis of all anionic cell-wall polymers in Bacillus subtilis 168.

Sequence homologies suggest that the Bacillus subtilis 168 tagO gene encodes UDP-N-acetylglucosamine:undecaprenyl-P N-acetylglucosaminyl 1-P transferase, the enzyme responsible for catalysing the first step in the synthesis of the teichoic acid linkage unit, i.e. the formation of undecaprenyl-PP-N-acetylglucosamine. Inhibition of tagO expression mediated by an IPTG-inducible P(spac) promoter led to the development of a coccoid cell morphology, a feature characteristic of mutants blocked in teichoic acid synthesis. Indeed, analyses of the cell-wall phosphate content, as well as the incorporation of radioactively labelled precursors, revealed that the synthesis of poly(glycerol phosphate) and poly(glucosyl N-acetylgalactosamine 1-phosphate), the two strain 168 teichoic acids known to share the same linkage unit, was affected. Surprisingly, under phosphate limitation, deficiency of TagO precludes the synthesis of teichuronic acid, which is normally induced under these conditions. The regulatory region of tagO, containing two partly overlapping sigma(A)-controlled promoters, is similar to that of sigA, the gene encoding the major sigma factor responsible for growth. Here, the authors discuss the possibility that TagO may represent a pivotal element in the multi-enzyme complexes responsible for the synthesis of anionic cell-wall polymers, and that it may play one of the key roles in balanced cell growth.

Sensitivity and specificity of the electrocardiogram to detect chronic myocardial infarction of the anteroseptal wall.

L`electrocardiograma és la primera eina diagnòstica fàcilment disponible per la detecció de l´infart a la práctica clínica. El seu valor va ser donat principalment amb estudis antics anatomopatològics. La ressonància magnètica cardíaca actualment és la tècnica d`elecció per la detecció de l`infart. Aquest estudi investiga el valor de l`electrocardiograma ( sensibilitat i especificitat) per detectar infarts de la zona anteroseptal. Conclusiò: la sensibilitat y la especificitat de quatre patents electrocardiogràfiques de la zona anteroseptal va ser valorada. Així mateix, encara que s`observin extenses ones Q en les derivacions anteriors la necrosis és usualment limitada si VL no está afectat. 3

Deletion of hypothetical wall teichoic acid ligases in Staphylococcus aureus activates the cell wall stress response.

The Staphylococcus aureus cell wall stress stimulon (CWSS) is activated by cell envelope-targeting antibiotics or depletion of essential cell wall biosynthesis enzymes. The functionally uncharacterized S. aureus LytR-CpsA-Psr (LCP) proteins, MsrR, SA0908 and SA2103, all belong to the CWSS. Although not essential, deletion of all three LCP proteins severely impairs cell division. We show here that VraSR-dependent CWSS expression was up to 250-fold higher in single, double and triple LCP mutants than in wild type S. aureus in the absence of external stress. The LCP triple mutant was virtually depleted of wall teichoic acids (WTA), which could be restored to different degrees by any of the single LCP proteins. Subinhibitory concentrations of tunicamycin, which inhibits the first WTA synthesis enzyme TarO (TagO), could partially complement the severe growth defect of the LCP triple mutant. Both of the latter findings support a role for S. aureus LCP proteins in late WTA synthesis, as in Bacillus subtilis where LCP proteins were recently proposed to transfer WTA from lipid carriers to the cell wall peptidoglycan. Intrinsic activation of the CWSS upon LCP deletion and the fact that LCP proteins were essential for WTA-loading of the cell wall, highlight their important role(s) in S. aureus cell envelope biogenesis.

In Bacillus subtilis W23, the duet sigmaXsigmaM, two sigma factors of the extracytoplasmic function subfamily, are required for septum and wall synthesis under batch culture conditions.

The synthesis of poly(RboP), the main Bacillus subtilis W23 teichoic acid, is encoded by tarDF-tarABIJKL operons, the latter being controlled by two promoters designated PtarA-int and PtarA-ext. Analysis by lacZ fusions reveals that PtarA-int activity exhibits sharp increases at the beginning and end of the transition between exponential and stationary growth phase. As confirmed by mRNA quantification, these increases are mediated by ECF sigma factors sigmaX and sigmaM respectively. In liquid media, strain W23 sigX sigM double mutants experience serious difficulties in the transition and stationary growth phases. Inactivation of sigmaX- and sigmaM-controlled regulons, which precludes transcription from PtarA-int, leads to (i) delays in chromosome segregation and septation and (ii) a transient loss of up to 30% of the culture OD or lysis. However, specific inactivation of PtarA-int, leading mainly to a shortage of poly(RboP), does not affect growth while, nevertheless, interfering with normal septation, as revealed by electron microscopy. The different sigM transcription in strains W23 and 168 is discussed. In W23, expression of tarA and sigM, which is shown to control divIC, is inversely correlated with growth rate, suggesting that the sigM regulon is involved in the control of cell division.

How Low Can We Go in Contrast-Enhanced CT Imaging of the Chest?: A Dose-Finding Cadaver Study Using the Model-based Iterative Image Reconstruction Approach.

RATIONALE AND OBJECTIVES: Dose reduction may compromise patients because of a decrease of image quality. Therefore, the amount of dose savings in new dose-reduction techniques needs to be thoroughly assessed. To avoid repeated studies in one patient, chest computed tomography (CT) scans with different dose levels were performed in corpses comparing model-based iterative reconstruction (MBIR) as a tool to enhance image quality with current standard full-dose imaging. MATERIALS AND METHODS: Twenty-five human cadavers were scanned (CT HD750) after contrast medium injection at different, decreasing dose levels D0-D5 and respectively reconstructed with MBIR. The data at full-dose level, D0, have been additionally reconstructed with standard adaptive statistical iterative reconstruction (ASIR), which represented the full-dose baseline reference (FDBR). Two radiologists independently compared image quality (IQ) in 3-mm multiplanar reformations for soft-tissue evaluation of D0-D5 to FDBR (-2, diagnostically inferior; -1, inferior; 0, equal; +1, superior; and +2, diagnostically superior). For statistical analysis, the intraclass correlation coefficient (ICC) and the Wilcoxon test were used. RESULTS: Mean CT dose index values (mGy) were as follows: D0/FDBR = 10.1 ± 1.7, D1 = 6.2 ± 2.8, D2 = 5.7 ± 2.7, D3 = 3.5 ± 1.9, D4 = 1.8 ± 1.0, and D5 = 0.9 ± 0.5. Mean IQ ratings were as follows: D0 = +1.8 ± 0.2, D1 = +1.5 ± 0.3, D2 = +1.1 ± 0.3, D3 = +0.7 ± 0.5, D4 = +0.1 ± 0.5, and D5 = -1.2 ± 0.5. All values demonstrated a significant difference to baseline (P < .05), except mean IQ for D4 (P = .61). ICC was 0.91. CONCLUSIONS: Compared to ASIR, MBIR allowed for a significant dose reduction of 82% without impairment of IQ. This resulted in a calculated mean effective dose below 1 mSv.

Ruling out coronary heart disease in primary care patients with chest pain : a clinical prediction score

ABSTRACT: BACKGROUND: Chest pain raises concern for the possibility of coronary heart disease. Scoring methods have been developed to identify coronary heart disease in emergency settings, but not in primary care. METHODS: Data were collected from a multicenter Swiss clinical cohort study including 672 consecutive patients with chest pain, who had visited one of 59 family practitioners' offices. Using delayed diagnosis we derived a prediction rule to rule out coronary heart disease by means of a logistic regression model. Known cardiovascular risk factors, pain characteristics, and physical signs associated with coronary heart disease were explored to develop a clinical score. Patients diagnosed with angina or acute myocardial infarction within the year following their initial visit comprised the coronary heart disease group. RESULTS: The coronary heart disease score was derived from eight variables: age, gender, duration of chest pain from 1 to 60 minutes, substernal chest pain location, pain increases with exertion, absence of tenderness point at palpation, cardiovascular risks factors, and personal history of cardiovascular disease. Area under the receiver operating characteristics curve was of 0.95 with a 95% confidence interval of 0.92; 0.97. From this score, 413 patients were considered as low risk for values of percentile 5 of the coronary heart disease patients. Internal validity was confirmed by bootstrapping. External validation using data from a German cohort (Marburg, n = 774) revealed a receiver operating characteristics curve of 0.75 (95% confidence interval, 0.72; 0.81) with a sensitivity of 85.6% and a specificity of 47.2%. CONCLUSIONS: This score, based only on history and physical examination, is a complementary tool for ruling out coronary heart disease in primary care patients complaining of chest pain.

Northern Ireland Chest Heart & Stroke - Research Grants for 2010 in Respiratory and Cardiovascular Disease

To download an Application Form, Guidance Notes and other information, please visit the website www.nichsa.com or contact Caoimhe Devlin, Research Assistant by email: cdevlin@nichsa.com or phone: 02890 266714 / 02890 320184 ext 248.

Northern Ireland Chest Heart and Stroke Association

The project will develop a relationship with the pharmacist in Bessbrook and Kilkeel. 3 sessions will be held in each area allowing time for 1-1 support for clients and carers.

Mechanisms for suppressing NADPH oxidase in the vascular wall

Oxidative stress underlies many forms of vascular disease as well as tissue injury following ischemia and reperfusion. The major source of oxidative stress in the artery wall is an NADPH oxidase. This enzyme complex as expressed in vascular cells differs from that in phagocytic leucocytes both in biochemical structure and functions. The crucial flavin-containing catalytic subunits, Nox1 and Nox4, are not found in leucocytes, but are highly expressed in vascular cells and upregulated with vascular remodeling, such as that found in hypertension and atherosclerosis. The difference in catalytic subunits offers the opportunity to develop "vascular specific" NADPH oxidase inhibitors that do not compromise the essential physiological signaling and phagocytic functions carried out by reactive oxygen and nitrogen species. Nitric oxide and targeted inhibitors of NADPH oxidase that block the source of oxidative stress in the vasculature are more likely to prevent the deterioration of vascular function that leads to stroke and heart attack, than are conventional antioxidants. The roles of Nox isoforms in other inflammatory conditions are yet to be explored.

Traumatic mitral valve injury after blunt chest trauma: a case report and review of the literature.

Mitral valve injury after blunt chest trauma is a rare occurrence. We recently admitted a patient with severe traumatic mitral regurgitation who was successfully treated with surgery. Review of the literature aimed at taking an inventory of cases of traumatic nonpenetrating mitral insufficiency that were operated on, since the earliest report in 1964. Eighty-two cases were found and analyzed allowing for a better understanding of the epidemiology, etiology, natural history, pathology, and treatment of this rare condition. The most common lesions reach the papillary muscles (PM), followed by the chordae and then the mitral valve leaflets. Among the 82 cases reported that have been treated with surgery, 57% required a valve replacement. More than half of the patients had a PM injury with a complete or partial rupture. When the rupture is complete, and especially when it involves the anterior PM, the clinical picture is most always acute with clinically important hemodynamic repercussions, often necessitating emergency surgery, most of the time with mitral valve replacement. One must always suspect traumatic mitral injury after blunt chest trauma. The most common mitral lesions affect the PM. The clinical course can be indolent or devastating, and most often requires urgent or delayed surgical treatment, either with mitral valve repair or replacement.