Cooperative effects on the compaction of DNA fragments by the nucleoid protein H-NS and the crowding agent PEG probed by Magnetic Tweezers.

BACKGROUND: DNA bridging promoted by the H-NS protein, combined with the compaction induced by cellular crowding, plays a major role in the structuring of the E. coli genome. However, only few studies consider the effects of the physical interplay of these two factors in a controlled environment. METHODS: We apply a single molecule technique (Magnetic Tweezers) to study the nanomechanics of compaction and folding kinetics of a 6 kb DNA fragment, induced by H-NS bridging and/or PEG crowding. RESULTS: In the presence of H-NS alone, the DNA shows a step-wise collapse driven by the formation of multiple bridges, and little variations in the H-NS concentration-dependent unfolding force. Conversely, the DNA collapse force observed with PEG was highly dependent on the volume fraction of the crowding agent. The two limit cases were interpreted considering the models of loop formation in a pulled chain and pulling of an equilibrium globule respectively. CONCLUSIONS: We observed an evident cooperative effect between H-NS activity and the depletion of forces induced by PEG. GENERAL SIGNIFICANCE: Our data suggest a double role for H-NS in enhancing compaction while forming specific loops, which could be crucial in vivo for defining specific mesoscale domains in chromosomal regions in response to environmental changes.

Effect of intracoronary bone marrow-derived mononuclear cell injection early and late after myocardial infarction on CMR-derived myocardial strain.

BACKGROUND: Studies indicate no clear impact of intracoronary injection of bone-marrow unselected mononuclear cells (BM-MNC) after acute myocardial infarction (AMI) on left-ventricular function (LVEF). Strain parameters by cardiovascular magnetic resonance (CMR) have been proposed to be more sensitive to functional changes of the heart. The aim of the present study was to assess changes of global longitudinal (GLS) and circumferential strain (GCS) in a group of patients treated with BM-MNC after AMI. METHODS: One-hundred and forty-nine patients with successfully reperfused AMI and LV dysfunction (LVEF<45%) were retrospectively included into this sub-study of the SWISS-AMI multicentre trial. Patients were divided into control (N = 54), early (5-7 days after AMI, N = 51) and late BM-MNC treatment groups (3-4 weeks, N = 44). The endpoint was the change of GLS and GCS as obtained from cine sequences 4 and 12 months after AMI using feature tracking algorithm. RESULTS: In unadjusted analyses, the absolute change of GLS for the early treatment group from baseline to 4 months was 2.5 ± 4.3 (p < 0.01), to 12 months 2.7 ± 5.7% (p = 0.004). For late treatment, it was 1.5 ± 4.0% (p = 0.039, 4 months) and 2.5 ± 5.6% (p = 0.015, 12 months). For controls 0.7 ± 4.7% (p = 0.378), 0.8 ± 3.9% (p = 0.253) respectively. Adjusting for different baseline values, neither an overall treatment effect (both time-points) of BM-MNC nor a treatment time-related (only early or late) effect could be shown for all functional parameters. CONCLUSIONS: Among patients after AMI with successful reperfusion and LV dysfunction, intracoronary infusion of BM-MNC early or late after AMI did not improve global strain parameters at 4- or 12-months follow-up. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00355186.

[Functional dyspepsia and the satiety test: its usefulness in clinical practice]. / Dispepsia funcional y test de saciedad: utilidad en la práctica clínica.

INTRODUCTION: According to the Rome III Criteria, functional dyspepsia (FD) is classified as postprandial distress syndrome (PDS) and epigastric pain syndrome (EPS). On the other hand, the satiety test (ST) has been used to evaluate gastric accommodation and emptying, distinguishing healthy individuals from those with dyspepsia. AIMS: To determine whether the ST can distinguish dyspeptic individuals from healthy ones and to evaluate its usefulness in differentiating the two FD subtypes. METHODS: Adults with FD were consecutively enrolled in a cross-sectional study within the time frame of August 2011 and October 2012. Healthy subjects participated as controls. The ST consisted of the intake of a nutritional supplement (Fortisip®, Nutricia Bagó®) at a constant speed; satiety was graded at 5-minute intervals (1 to 5 points). Intake was suspended when the maximum score was reported. The total ingested volume and caloric intake was recorded and the Mann-Whitney U test was used in the statistical analysis. RESULTS: The study included 39 dyspeptic patients and 20 control individuals. The patients were predominantly women (84.6 vs. 25%; p < 0.0001) and they were similar in age (39.59 ± 13.53 vs. 34.70 ± 9.85 years) and BMI (24.32 ± 3.52 vs. 25.82 ± 3.34 kg/m2) with respect to the controls. The FD subtype percentages were PDS: 61%, EPS: 31%, and Mixed syndrome: 8%. There was a lower ingested volume and caloric intake on the part of the dyspeptic patients (185 vs. 300 ml and 277 vs. 520 Kcal, respectively. Both: P<.001). No differences in the ST were observed between the two pure dyspepsia subtypes. CONCLUSIONS: There was a difference in the ST between healthy individuals and those with dyspepsia, but the ingested volume and caloric intake in the two FD subtypes were similar.

Long-term patient benefit with biodegradable polymer biolimus eluting stent.

The introduction of bare metal stents in the early 1990 and of 1st generation drug eluting stents (DES) in the early 2000 defined a new era in interventional cardiology. DES dramatically reduced instant restenosis and the need of revascularization after percutaneous coronary intervention. However, this increased efficacy came at the cost of delayed vascular healing and subsequent late adverse event such as late stent thrombosis. Second generation DES appears even more efficient and safer than 1st generation DES, providing exciting perspectives for the near future. A new era has started with the development of bio-absorbable polymers. Biodegradable polymer eluting stents, such as the biolimus A9 eluting stent showed non-inferiority to durable polymer sirolimus eluting stent and, by reducing the risk of cardiac events associated with very late stent thrombosis, might improve long-term clinical outcomes in a variety of patients including chronic stable coronary artery disease and acute coronary syndromes. Biodegradable polymer DES are more likely to define the 3rd generation DES. The goal of future development is to further increase safety and efficacy of DES.

Effects of percutaneous transluminal angioplasty and endovascular brachytherapy on vascular remodeling of human femoropopliteal artery: 2 years follow-up by noninvasive magnetic resonance imaging.

OBJECTIVES: We aimed to assess in vivo the long-term effects of percutaneous transluminal angioplasty (PTA) and endovascular brachytherapy (EVBT) on vessel wall by serial MRI. METHODS: Twenty patients with symptomatic stenosis of the femoropopliteal artery were randomly assigned to PTA (n=10) or PTA+EVBT (n=10, 14Gy by gamma-source). High-resolution MRI was performed prior, at 24-hours, 3-months, and 24-months after intervention. MRI data were analyzed by an independent, blinded observer. RESULTS: The effects of both procedures on vessel wall at 24-hours and 3-months have been reported. Despite similar percent decrease in lumen area between 3- and 24-months in both groups (-8% for PTA and -11% for PTA+EVBT), at 24-months lumen area gain compared to baseline was +30% in PTA versus +82% in PTA+EVBT (p<0.05). Total vessel area, which was increased at 24-hours and 3-months, returned to pre-treatment value in both groups. CONCLUSIONS: We demonstrated non-invasively that restenosis and inward remodeling after PTA are delayed by EVBT. At 24-months, patients treated with brachytherapy have larger lumen than those treated with PTA alone. The decrease in luminal and total vessel area between 3- and 24-months after EVBT indicates that the restenotic and remodeling process is not abolished but delayed with this therapy.

Elevated gastric lesions: virtual gastroscopy.

With the development of multidetector computed tomography and the improvement in the capabilities of workstations, the use of high-quality three-dimensional reconstructions and virtual images can be applied to organs other than the colon such as the stomach. As a noninvasive technique, virtual gastroscopy represents an alternative to conventional endoscopy for the detection of elevated lesions. Findings of this technique are illustrated.

Estudio epidemiológico de infección por Helicobacter pylori en el cono urbano bonaerense / Epidemology of helicobacter pylori infection in the province of Buenos Aires

Hemos planteado el presente trabajo, teniendo en cuenta los siguientes aspectos: describir las características epidemiológicas y demográficas en la población estudiada y además caracterizar especialmente los factores higiénicos, sanitarios y culturales que por su heterogeneidad, tuvieron influencia en la capacidad de infección por el Helicobacter Pylori

Estudio epidemiológico de infección por Helicobacter pylori en el cono urbano bonaerense / Epidemology of helicobacter pylori infection in the province of Buenos Aires

Hemos planteado el presente trabajo, teniendo en cuenta los siguientes aspectos: describir las características epidemiológicas y demográficas en la población estudiada y además caracterizar especialmente los factores higiénicos, sanitarios y culturales que por su heterogeneidad, tuvieron influencia en la capacidad de infección por el Helicobacter Pylori

[Coffee--poison or medicine?]. / Kaffee--Gift oder Medizin?

Intake of coffee, one of the most common beverages worldwide, has often been discussed as a potential cardiovascular risk factor. However, definitive data about this topic are missing and newer studies even point out for a favorable rather than hazardous effect. Despite many studies no clear association between coffee and the risk of hypertension, myocardial infarction and other cardiovascular diseases was found. Recent publications suggest that moderate coffee intake does not represent a health hazard, but may even be associated with beneficial effects on the cardiovascular system and diabetes.

[The sweet secret of dark chocolate]. / Das süsse Geheimnis der dunklen Schokolade.

For centuries dark chocolate has been known for its taste as well as its beneficial effects on health. Mainly polyphenols, a heterogeneous group of molecules, have been associated with antioxidant and immunomodulatory properties. Furthermore they inhibit primary hemostasis and pathways associated with platelet activation and aggregation.

Real time magnetic resonance guided endomyocardial local delivery.

OBJECTIVE: To investigate the feasibility of targeting various areas of left ventricle myocardium under real time magnetic resonance (MR) imaging with a customised injection catheter equipped with a miniaturised coil. DESIGN: A needle injection catheter with a mounted resonant solenoid circuit (coil) at its tip was designed and constructed. A 1.5 T MR scanner with customised real time sequence combined with in-room scan running capabilities was used. With this system, various myocardial areas within the left ventricle were targeted and injected with a gadolinium-diethylenetriaminepentaacetic acid (DTPA) and Indian ink mixture. RESULTS: Real time sequencing at 10 frames/s allowed clear visualisation of the moving catheter and its transit through the aorta into the ventricle, as well as targeting of all ventricle wall segments without further image enhancement techniques. All injections were visualised by real time MR imaging and verified by gross pathology. CONCLUSION: The tracking device allowed real time in vivo visualisation of catheters in the aorta and left ventricle as well as precise targeting of myocardial areas. The use of this real time catheter tracking may enable precise and adequate delivery of agents for tissue regeneration.

Colonoscopia virtual. Experiencia en 500 pacientes / Virtual Colonoscopy. Experience in 500 patients

OBJECTIVE: To show our experience and results in Virtual Colonoscopy (VC). MATERIAL AND METHOD: Five hundred patients with personal or familial history of colorectal carcinoma and/or adenomas, or any kind of coloproctologic symptoms were studied. VCs were practiced using a helical CT scanner (300 patients) and a multislice CT scanner (200 patients) a few hours after Conventional Colonoscopy (CC), considered the gold standard. The patients were evaluated in a prospective blind study, to determine sensitivity and specificity of VC. Findings were classified as: 1) normal studies; 2) studies with pathological findings. This one was subdivided into: 2a) Lesions below 5 mm., 2b) Lesions between 5-9 mm., 2c) Lesions above 9 mm. RESULTS: VC detected 253 normal studies whereas CC only detected 233. The sensitivity and specificity for each subgroup were: 2a) 87.8% and 86.9%; 2b) 95.6% and 91.4%; 2c) 100.0% and 100.0% respectively. CONCLUSION: VC is a feasible and useful method for evaluating the entire colon. It is well tolerated, it has no complications and a high sensitivity and specificity for elevated lesions, especially the ones above or equal to 5 mm. (AU)

Linfoma primario de esofago en una paciente con SIDA / Primary esophageal lymphoma in a patient with AIDS

Primary esophageal lymphomas are extremely rare. We report a primary esophageal T cell lymphoma of a diffuse large cell phenotype B in a patient with AIDS. Also we reviewed other published cases. The diagnosis of this complication should be considered in HIV seropositive patients with progressive displagia and endoscopic findings of masses, polyps or ulcerations and, specially in those unresponsive to antifungal or antiviral therapy. Biopsy and histopathologic studies are needed to confirm the diagnosis. (AU)

Colonoscopia virtual. Experiencia en 500 pacientes / Virtual Colonoscopy. Experience in 500 patients

OBJECTIVE: To show our experience and results in Virtual Colonoscopy (VC). MATERIAL AND METHOD: Five hundred patients with personal or familial history of colorectal carcinoma and/or adenomas, or any kind of coloproctologic symptoms were studied. VCs were practiced using a helical CT scanner (300 patients) and a multislice CT scanner (200 patients) a few hours after Conventional Colonoscopy (CC), considered the gold standard. The patients were evaluated in a prospective blind study, to determine sensitivity and specificity of VC. Findings were classified as: 1) normal studies; 2) studies with pathological findings. This one was subdivided into: 2a) Lesions below 5 mm., 2b) Lesions between 5-9 mm., 2c) Lesions above 9 mm. RESULTS: VC detected 253 normal studies whereas CC only detected 233. The sensitivity and specificity for each subgroup were: 2a) 87.8% and 86.9%; 2b) 95.6% and 91.4%; 2c) 100.0% and 100.0% respectively. CONCLUSION: VC is a feasible and useful method for evaluating the entire colon. It is well tolerated, it has no complications and a high sensitivity and specificity for elevated lesions, especially the ones above or equal to 5 mm.

Linfoma primario de esofago en una paciente con SIDA / Primary esophageal lymphoma in a patient with AIDS

Primary esophageal lymphomas are extremely rare. We report a primary esophageal T cell lymphoma of a diffuse large cell phenotype B in a patient with AIDS. Also we reviewed other published cases. The diagnosis of this complication should be considered in HIV seropositive patients with progressive displagia and endoscopic findings of masses, polyps or ulcerations and, specially in those unresponsive to antifungal or antiviral therapy. Biopsy and histopathologic studies are needed to confirm the diagnosis.

Integration of vascular biology and magnetic resonance imaging in the understanding of atherothrombosis and acute coronary syndromes.

The interaction between the vulnerable atherosclerotic plaque prone to disruption and thrombus formation is the cornerstone of acute coronary syndrome (ACS). Although distinct from one another, the atherosclerotic and thrombotic processes appear to be interdependent, hence the term atherothrombosis. Inflammation is a crucial common pathophysiological mechanism. Overall, the association of plaque vulnerability and ACS has been well documented. Given the multifactorial origin of atherothrombosis the best preventive approach should be aggressive management of all the risk factors. New interventions should be directed toward decreasing vulnerability of the lesions thereby decreasing the risk of ACS.