[Utility of capsule endoscopy with flexible spectral imaging color enhancement in the diagnosis of small bowel lesions]

INTRODUCTION

Capsule endoscopy (CE) is the technique of choice to detect small bowel lesions. Flexible spectral imaging color enhancement (FICE) software has recently been incorporated into the new RAPID 6.0 workstation, which allows three distinct patterns to be visualized in the mucosal structure according to different wavelengths. The aim of this study was to evaluate whether CE-FICE is more effective in detecting lesions than standard visualization.

PATIENTS AND METHODS

Fifty lesions were detected by CE in 41 consecutive patients in 2010. These patients were administered PillCamTM SB2 in our center and were classified into three groups: 1) vascular lesions and angiodysplasias (18 lesions), 2) erosions and ulcers (18 lesions) and 3) polyps and tumors (14 lesions). Subsequently, these lesions were independently analyzed with the available FICE patterns by three endoscopists, who assigned them a score according to the changes in the visualization of each FICE mode: +2, strong improvement; +1, slight improvement; 0, no relevant changes; -1, slight worsening; -2, clear worsening. When the sum of the scores of the three observers was 3 or more, visualization was considered to have improved; a score of 2 to -2 indicated no change; and a score of from -3 to -6 indicated poorer visualization.

RESULTS

The FICE 1 mode improved visualization of angiodysplastic and vascular lesions in 16/18 patients (88.9%) and that of erosions/ulcers in 14/18 patients (77.8%). The FICE 2 mode improved these lesions in 88.9% and 55.5%, respectively. The FICE 3 mode only improved visualization of these lesions in 5/18 (27.7%) and 1/18 patients (5.5%), respectively. Likewise, the distinct FICE modes improved visualization of polyps/tumors in 2/14 (14.2%), 3/13 (21.4%) and 4/14 (28.5%) for FICE 1, 2 and 3, respectively.

CONCLUSIONS

The application of CE-FICE modes 1 and 2 could improve the characterization of angiodysplastic/vascular lesions and erosions or ulcers in small bowel lesions. However, FICE 3 seems to provide no significant advantages. None of the CE-FICE modes seems to improve the characterization of polyps and tumors.

[Optimization of ascitic fluid culture in spontaneous bacterial peritonitis]

INTRODUCTION AND AIMS

Spontaneous bacterial peritonitis (SBP) is ascitic fluid (AF) infection in the absence of an intraperitoneal source of infection in patients with liver disease and portal hypertension. The aim of this study was to evaluate the yield of microbiological cultures to optimize their collection and systematic implementation in routine clinical practice.

METHODS

We analyzed two cohorts: the first consisted of retrospective data from the clinical records of 156 consecutive episodes of SBP from January 2003 to December 2005 (group R), and the second was composed of data collected prospectively from October 2007 to October 2008, consisting of 79 episodes (group P), with systematic inoculation of 10 cc of AF in each blood culture bottle.

RESULTS

No significant differences were demonstrated in baseline epidemiological or clinical characteristics among episodes, except the more frequent presence of alcoholic liver disease and the incidence of tense ascites, paralytic ileus and kidney failure at diagnosis in group P. Microbiological isolation in AF was achieved in 12.2% of the episodes in group R compared with 53.2% in group P (p = 0.001) and 8.5 and 26.6% (p = 0.001) in blood culture, respectively. Microbiological isolation was achieved in 65.8% of episodes in group P versus 19.2% in group R (OR 8; 95% CI: 4.4-14.9; p = 0.001). The most frequently isolated organism in AF in group P was Escherichia coli (42.9%).

CONCLUSIONS

Optimizing the diagnostic procedure in cirrhotic patients with ascites significantly increases diagnostic microbiologic performance.

Voltage gating of Shaker K+ channels. The effect of temperature on ionic and gating currents

Ionic (Ii) and gating currents (Ig) from noninactivating Shaker H4 K+ channels were recorded with the cut-open oocyte voltage clamp and macropatch techniques. Steady state and kinetic properties were studied in the temperature range 2-22 degreesC. The time course of Ii elicited by large depolarizations consists of an initial delay followed by an exponential rise with two kinetic components. The main Ii component is highly temperature dependent (Q10 > 4) and mildly voltage dependent, having a valence times the fraction of electric field (z) of 0.2-0.3 eo. The Ig On response obtained between -60 and 20 mV consists of a rising phase followed by a decay with fast and slow kinetic components. The main Ig component of decay is highly temperature dependent (Q10 > 4) and has a z between 1.6 and 2.8 eo in the voltage range from -60 to -10 mV, and approximately 0.45 eo at more depolarized potentials. After a pulse to 0 mV, a variable recovery period at -50 mV reactivates the gating charge with a high temperature dependence (Q10 > 4). In contrast, the reactivation occurring between -90 and -50 mV has a Q10 = 1.2. Fluctuation analysis of ionic currents reveals that the open probability decreases 20% between 18 and 8 degreesC and the unitary conductance has a low temperature dependence with a Q10 of 1.44. Plots of conductance and gating charge displacement are displaced to the left along the voltage axis when the temperature is decreased. The temperature data suggests that activation consists of a series of early steps with low enthalpic and negative entropic changes, followed by at least one step with high enthalpic and positive entropic changes, leading to final transition to the open state, which has a negative entropic change.

Transitions near the open state in Shaker K(+)-channel: probing with temperature

Ionic currents from non-inactivating Shaker K(+)-channels were expressed in Xenopus oocytes and recorded with the cut-open oocyte voltage clamp technique. Kinetic properties of ionic currents were studied between 1.4 and 19 degrees C. The forward step of the last transition (...C --> O) of the activation pathway, just before the channel opening, was studied by the recovery of the ionic current after a short interval (< 500 microseconds) at a hyperpolarized potential (-90 mV) between two identical depolarizing pulses (0, 40 or 100 mV). Ionic currents under these experimental conditions are described by at least three kinetic components. The predominant kinetic component (corresponding to the ...C --> O transition) has a low temperature dependence (activation energy, Ea, around -5 kcal/mol) and it is voltage independent, suggesting that this step does not carry charge and has a mainly entropic energy barrier. The backward step (O --> C...) was studied from ionic tail currents at -120 mV after pulsing to 40 mV. The closure of the channel has a high temperature dependence (Q10 > 4), having an Ea of 24-25 kcal/mol. The closure of the channel also is voltage dependent, having a valence times fraction of the electric field, z beta of 0.5 eo. We conclude that the transition from the closed to the opened state has a net decrease in entropy and enthalpy, suggesting that the channel gets more ordered when it is open.