Appetite and obesity: a gastroenterologist''s perspective

This review focuses on the gastrointestinal tract's control of appetite and interventions directed to the gut that are effective in the treatment of obesity. It examines the evidence linking gut hormones to the control of both appetite and upper gastrointestinal motility, the evidence that stomach function is altered and contributes to satiation in obesity and outlines the principles of therapy for obesity which are directed at the gastrointestinal tract. These therapies impair fat absorption or alter stomach functions through pharmacological, device, endoscopic, or surgical approaches. Gastroenterologists need to understand the role of factors controlling appetite in order to effectively manage the increasing number of obese patients and the ways the gut function may be altered as a result of the treatments and their complications.     

Evaluation of the clinical, hemodynamic and neurohormonal response to levosimendan administration in decompensated heart failure patients. One-month follow-up.

INTRODUCTION: Levosimendan is an inodilatory drug with hemodynamic effects in patients with decompensated chronic heart failure. AIM: Short-term (one month) evaluation of clinical, hemodynamic and neurohormonal changes in patients with decompensated chronic heart failure undergoing levosimendan therapy. METHODS: Twenty-six (21 male) consecutive patients were studied, corresponding to 32 levosimendan administrations (bolus + 24h infusion), aged 56.7+/-13.0 years, with decompensated chronic heart failure, in NYHA functional class III-IV (78.1% in class IV), and cardiac index (CI) <2.5 l/min/m2. Clinical (NYHA class), non-invasive hemodynamic (echocardiography) and neurohormonal (Elecsys ECLIA NT-ProBNP) evaluations were performed before levosimendan administration and on days 1, 4, 10 and 30. RESULTS: 1) Until day 10, there was a progressive decrease in NT-ProBNP values and weight (p<0.001), with an increase in CI (p<0.001); 2) NYHA functional class improved progressively, with 76% of the patients in NYHA class II at day 30; 3) NT-ProBNP values at day 1 correlated inversely (r=-0.414; p=0.024) with CI at day 4; and 4) the absolute decrease in NT-ProBNP values at day 4 (relative to baseline values) correlated with weight loss at day 4 (r=0.495, p=0.005), day 10 (r=0.424, p=0.031) and day 30 (r=0.486, p=0.030). CONCLUSION: Levosimendan therapy in patients with decompensated chronic heart failure contributes to progressive NYHA class improvement. The variations seen in NYHA class and hemodynamics was reflected in changes in NT-ProBNP.     

Isolated right ventricular dysfunction in systemic sclerosis: latent pulmonary hypertension?

Right ventricular function is frequently abnormal in patients with systemic sclerosis, but whether this is related to pulmonary vascular complications of the disease is unclear. Standard echocardiography with tissue Doppler imaging was performed at rest and during exercise for the study of right ventricular function and pulmonary circulation in 25 consecutive systemic sclerosis patients and in 13 age-matched healthy controls. When compared with the controls, the patients had no difference in systolic right ventricular pressure gradient, but a decreased pulmonary flow acceleration time, and increased right ventricular free wall thickness and end-diastolic dimensions. At the tricuspid annulus, the E maximal velocity was decreased (8.9 +/- 4 versus 11.7 +/- 2.3 cm.s(-1)) and the isovolumic relaxation time corrected to RR interval was increased (6.5 +/- 2.9 versus 4.5 +/- 2.5%). The tissue Doppler imaging profile at the mitral annulus was similar in both groups. At exercise, 18 patients had a decreased maximum workload and cardiac output, no change in systolic right ventricular pressure gradient, but an increase in the slope of pulmonary artery pressure/flow relationships. These results suggest that patients with systemic sclerosis may present with latent pulmonary hypertension as a likely cause of right ventricular diastolic dysfunction, as revealed by stress echocardiography and tissue Doppler imaging.     

A note on the half-life of 209Po.

The widely adopted value of (102+/-5)a for the (209)Po half-life, which is based on a single determination reported in 1956, appears to be in error by a large factor. Decay data from two separate primary standardizations of a (209)Po solution standard, conducted approximately 12 years apart, are inconsistent with the adopted value and its assigned uncertainty. An estimated half-life, larger than the adopted value by about 25%, is more consistent with the standardization data. A longer half-life is also supported by measurements on a recently standardized (210)Pb solution standard.     

Right frontal event related EEG coherence (ERCoh) differentiates good from bad performers of the Wisconsin Card Sorting Test (WCST).

AIM: To investigate changes in Event-Related Coherence (ERCoh) associated to good and bad resolution of the Wisconsin Card Sorting Test (WCST). METHODS: Event-Related Potentials (ERPs) were recorded from a sample of 30 university students while they performed a computerized version of the WCST. ERCoh was calculated for frontal and parietal electrodes for two specific moments: immediately before the response and after the feedback cues. RESULTS: Bad performers presented significantly reduced ERCoh at the right frontal region (in alpha, beta-1 and beta-2 bands), while no consistent group differences emerged for parietal ERCoh. Furthermore, the strength of functional coupling (ERCoh) between midfrontal and right-frontal electrodes was a good predictor of WCST behavioural parameters, such as the percentage of perseverative errors or the number of categories achieved. CONCLUSIONS: The results suggest that the right prefrontal cortex is specifically involved in executive functions, such as planning and foresight, tapped by the WCST. Although the specificity of the WCST to explore frontal lesions has been recently questioned, the present findings support that prefrontal areas are specifically involved in the successful resolution of the test by healthy subjects.     

Surgery for right ventricle to pulmonary artery conduit obstruction: risk factors for further reoperation.

OBJECTIVE: To identify the surgical approaches and risk factors which influence longevity of right ventricle to pulmonary artery (RV-PA) conduits following first reoperation for obstruction. METHODS: Between January 1993 and August 2003, 114 patients underwent 141 reoperations for RV-PA conduit obstruction. Diagnoses included 'Truncus Arteriosus' (n=52), 'Pulmonary atresia/Tetralogy of fallot' (n=39), 'Double outlet right ventricle' (n=10), 'Transposition of great arteries, VSD, and pulmonary atresia' (n=9), and the 'Ross operation' (n=4). All patients had undergone a previous biventricular repair. The first reoperation for conduit obstruction was performed in 112 hospital survivors by: total conduit replacement (Group A, n=73) with valved (homograft=10 and xenograft=54) or non-valved (n=9) conduit, and patch enlargement of the obstructed RV outflow tract with preservation of the posterior and sides of the conduit wall after removing of the fibrocalcific peel and degenerated valve (Group B, n=39). Mean age at first reoperation was 8.8+/-6.7 and 7.5+/-5.3 years in patients of groups A and B, respectively. Seven patients in Group A and 18 in Group B required a second reoperation and two patients in Group B a third reoperation. RESULTS: There were two hospital deaths and no late deaths. Mean follow-up was 5.8+/-3.2 years. Risk factors for second reoperation by univariate analysis were: homograft conduit use (P=0.004), Group B surgical approach (P=0.0001), higher RV-PA systolic pressure gradient at discharge (P=0.02), and age <5-years-old (P=0.01). Multivariate analysis showed that inclusion in Group B and younger age (<5-years-old) at repair were independent risk factors for second reoperation. Group B surgical approaches had higher RV-PA systolic pressure gradient at discharge (P=0.02) and required more PA bifurcation repair at the time of second reoperation (P=0.05). Freedom from second reoperation for conduit obstruction was significantly higher in Group A patients at 5 and 8 years (P<0.04) and those with xenografts rather than homograft (P=0.04). CONCLUSIONS: Our results support the optimal surgical approach for RV-PA conduit obstruction is total replacement with a xenograft. RV outflow reconstruction by other techniques without complete dissection of PA bifurcation does not completely relieve the stenosis and could cause early restenosis. Higher systolic gradients at discharge and younger age at first reoperation are predictors of earlier reoperation.     

Stem cell research and cell transplantation for myocardial regeneration.

Several human organs are not capable of functional regeneration following a tissue defect and react with scar formation. In stem cell transplantation, undifferentiated or partly differentiated precursor cells are applied to defective tissue for therapeutic regeneration. After promising preclinical investigations, the transplantation of autologous stem cells for myocardial infarction treatment is being transferred to clinical use. Mesenchymal stem cells and endothelial precursor cells derived from the bone marrow or circulating blood as well as skeletal myoblasts are employed in clinical trials. Furthermore, indications for cell transplantation and delivery routes vary considerably throughout current investigations. Initial results suggest a potential for restoration of cardiac function in stem cell-treated patients; however, the mechanisms are not fully understood. This overview will focus on objectives, recent achievements, and future perspectives of diverse stem cell transplantation approaches.     

18F-FDG PET/CT delayed images after diuretic for restaging invasive bladder cancer.

PET with (18)F-FDG has been considered of limited value for detection of bladder cancer because of the urinary excretion of the tracer. The purpose of this study was to investigate the role of PET/CT in the detection and restaging of bladder cancer using furosemide and oral hydration to remove the excreted (18)F-FDG from the bladder. METHODS: Seventeen patients with bladder cancer (11 without cystectomy, 6 with total cystectomy and urinary diversion) underwent (18)F-FDG PET/CT from head to the upper thighs 60 min after the intravenous injection of 370 MBq of (18)F-FDG. Additional pelvic images were acquired 1 h after the intravenous injection of furosemide and oral hydration. PET/CT findings were confirmed by MRI, cystoscopy, or biopsy. RESULTS: PET/CT was able to detect bladder lesions in 6 of 11 patients who had not undergone cystectomy. These images changed the PET/CT final reading in 7 patients: Recurrent bladder lesions were detected in 6 patients, pelvic lymph node metastases in 2 patients, and prostate metastasis in 1. This technique overcame the difficulties posed by the urinary excretion of (18)F-FDG. Hypermetabolic lesions could be easily detected by PET and precisely localized in the bladder wall, pelvic lymph nodes, or prostate by CT. Seven of 17 patients (41%) were upstaged only after delayed pelvic images. CONCLUSION: Detection of locally recurrent or residual bladder tumors can be dramatically improved using (18)F-FDG PET/CT with delayed images after a diuretic and oral hydration.