The value of precontrast thoraco-abdominopelvic CT in polytrauma patients.

PURPOSE: To evaluate the utility and radiation dose of thoraco-abdominopelvic precontrast CT in polytrauma patients. MATERIALS AND METHODS: We examined retrospectively 125 patients who underwent a thoraco-abdominopelvic CT for trauma. Two radiologists, independently, evaluated precontrast CT acquisition and two other radiologists examined the contrast-enhanced scans. A further two radiologists assessed both the acquisitions. Mean value of sensitivity (SE), specificity (SP), positive predictive value (PPV) and negative predictive value (NPV) were calculated by each group of radiologists. For 104 patients, CTDIvol, DLP data and individual mean size were collected to calculate effective dose. RESULTS: Mean values of SE, SP, PPV and NPV of findings of radiologists who assessed contrast-enhanced acquisitions were respectively: SE=85%, SP=98%, PPV=86%, NPV=88% versus: SE=43%, SP=95%, PPV=69%, NPV=88% of radiologists who examined non-contrast-enhanced scans. Mean values of radiologists who analyzed both acquisitions were: SE=80%, SP=97%, PPV=80%, NPV=88%. Neither the precontrast scans nor the precontrast and postcontrast scans together provided additional useful information compared to the single contrast-enhanced acquisition. Patients received a mean dose of 12 mSv for the precontrast CT. CONCLUSIONS: Precontrast CT acquisition did not provide significant information in trauma patients, exposing them to an unjustified radiation dose.

Polymethylmethacrylate membrane and serum free light chain removal: enhancing adsorption properties.

INTRODUCTION: Polymethylmethacrylate (PMMA) membranes can adsorb a wide variety of uremic toxins including serum free light chains (sFLC). However, limited data are available regarding the clinical use of PMMA in multiple myeloma patients and its maximum adsorption capacity in this setting. AIM: This study aimed to measure the capacity of PMMA to adsorb sFLC and identify strategies to improve its efficiency in clinical practice. METHODS: Ten patients with dialysis-dependent renal failure and high levels of sFLC were included in the study. Five patients received standard PMMA hemodialysis (HD; n = 18), while in the other 5 patients a new technique called enhanced adsorption dialysis (EAD) was used, which involves PMMA dialyzer replacement after 2 h (n = 19). In all patients, sFLC were measured at the beginning and at the end of each dialysis session to calculate the difference between start and end of treatment and the percentage removal. RESULTS: PMMA membranes reduced sFLC in both the PMMA HD and EAD groups. PMMA HD showed similar efficiency on κ and λ percentage removal (22.3 and 21.0%, respectively, n.s.) but, in contrast, had a significantly greater effect on the delta of sFLC in κ [1,555 mg/l (-511 to +6,027)] versus λ [390 mg/l (120-650)] treatments (p = 0.007). EAD treatments only partially increased percentage removal of κ sFLC (22.3-31.0%, p = 0.38), while they had a significantly great effect on λ (21.0-53.1%, p = 0.003). A positive linear correlation was found between delta sFLC and pre-HD sFLC concentrations in PMMA HD κ treatments (r = 0.68, p < 0.02) but not for λ treatments (r = 0.54, p = 0.21), while the analysis of patients receiving EAD demonstrated a strong positive correlation for both κ and λ subtypes (r = 0.81 and r = 0.85, respectively, p < 0.008). In EAD sessions, a positive linear correlation was shown between blood flow during treatment and percentage removal of sFLC (r = 0.58, p = 0.02); however, with PMMA HD such a correlation was not observed (r = 0.28, p = 0.25). CONCLUSIONS: PMMA membranes can efficiently adsorb sFLC, but the process is limited by membrane saturation and is different between κ and λ sFLC. The new EAD technique can greatly improve λ removal but only partially act on κ sFLC. Therefore, EAD should be considered a valid economic treatment option without side effects in particular subsets of patients for the removal of sFLC.

Intestinal interposition: the prevalence and clinical relevance of non-hepatodiaphragmatic conditions (non-Chilaiditi forms) documented by CT and review of the literature.

PURPOSE: This study was done to assess the prevalence and clinical impact of non-hepatodiaphragmatic interpositions in a sample of adult patients undergoing computed tomography (CT) for a variety of medical reasons. MATERIALS AND METHODS: From November 2008 to April 2009, two observers jointly examined the cases of intestinal interposition in 4,338 adults undergoing CT investigations. This study sought to identify not only hepatodiaphragmatic intestinal interpositions, defined as Chilaiditi, but also other forms of intestinal interposition, which we termed non-Chilaiditi. The latter were divided into five different classes on the basis of their anatomical relationships: splenorenal, retrogastric, hepatocaval, retrosplenic, and retrorenal. Moreover, a questionnaire investigating the clinical symptoms reported to be associated with Chilaiditi syndrome was given to patients exhibiting any form of intestinal interposition and to a control sample. Finally, clinical data related to the three groups were compared. RESULTS: Of the 4,338 patients examined, 130 (3%) were found to have intestinal interposition, for a total of 143 forms: 90 Chilaiditi and 53 non-Chilaiditi. Of the latter, 30 were splenorenal, 12 retrogastric, five hepatocaval, four retrosplenic and two retrorenal. Statistical analysis showed that the Chilaiditi group suffered most symptoms (24.4%), followed by the non-Chilaiditi group (18.9%) and control cases (10.8%). Our results were validated using the χ(2) test of significance. CONCLUSIONS: The number of non-Chilaiditi cases amounted to just over half the number of Chilaiditi cases, with the splenorenal form being by far the most frequent. Statistical analysis showed that patients with non-Chilaiditi forms of intestinal interposition had more symptoms than did controls.

Evaluation and predictive modeling of shelf life of minced beef stored in high-oxygen modified atmosphere packaging at different temperatures.

The aims were: (1) to follow the freshness decay of minced beef stored in high-oxygen modified atmosphere packaging at different temperatures (4.3, 8.1 and 15.5 degrees C) by applying traditional methods (microbiological counts, color evaluation, thiobarbituric acid assay TBA, headspace gas composition) and e-nose; (2) to model the decay kinetics to obtain information about the maximum shelf life as function of storage conditions. The minced beef, packaged in modified atmosphere was supplied by a manufacturer at the beginning of its commercial life. The study demonstrated the ability of the traditional methods to describe the kinetics of freshness decay. The modeling of the experimental data and the comparison with microbiological or chemical thresholds allowed the setting, for each index, of a stability time above which the meat was no longer acceptable. The quality decay of meat was also evaluated by the headspace fingerprint of the same set of samples by means of a commercial e-nose. A clear discrimination between "fresh" and "old" samples was obtained using PCA and CA, determining at each temperature a specific range of stability time. The mean value of the stability times calculated for each index was 9 days at 4.3 degrees C (recommended storage temperature), 3-4 days at 8.1 degrees C (usual temperature in household refrigerators) and 2 days at 15.5 degrees C (abuse temperature). Resolution of the stability times allowed calculation of mean Q(10) values, i.e. the increase in rate for a 10 degrees C increase in temperature. The results show that the Q(10) values from the traditional methods (3.6-4.0 range) overlapped with those estimated with e-nose and color indexes (3.4 and 3.9, respectively).

Chemical, physical and sensory attributes for the characterization of an Italian dry-cured sausage.

This work was designed to characterize Felino salami, an Italian dry-cured sausage. For this purpose, a wide range of chemical, physical and sensory parameters were studied in 29 samples. Seven chemical and physical variables were selected by using principal components analysis: namely, pH, NaCl/moisture, moisture/protein, soluble N/protein, lactic acid, elasticity index and sample luminosity (L(∗)). The first two principal components were significant according to double-cross validation and accounted for 79% of variance. The seven-variable chemometric model shows that variability in the first principal component is determined by variables expressing the acidity and the extent of lactic fermentation, while the second component is determined by variables expressing the degree of ripening and is related to the sensory scores maturation and hardness, and to salami age (p < 0.001). Sensory scores were evaluated by a multivariate method to verify the consonance among assessors as to the different attributes. The semi-trained panel was consonant and reliable for five of the nine sensory attributes evaluated. The predictive ability of the chemometric model for the sensory attributes was assessed with cross-validation.

Electroosmosis of polymer solutions in fused silica capillaries.

The classical von Smoluchowski equation predicts that the electroosmotic mobility generated by the wall zeta potential could be suppressed if the viscosity of the solution adjacent to the wall were extremely high. When performing runs in capillaries filled with polymer solutions (2% methyl cellulose solutions with viscosities of 25 cP), however, one consistently finds that the quenching of electroosmotic mobility is substantially less than predicted by the von Smoluchowski relationship. The electroosmotic flow is progressively suppressed with subsequent electrophoretic runs, suggesting a "dynamic coating" of the polymers onto the capillary wall. This progressive reduction of electroosmotic mobility tends to a plateau value which is still substantially higher than the value derived on the basis of the von Smoluchowski relationship. The following explanation is proposed: due to the very high shear rate in the electric double layer, the polymer molecules change their orientation and/or conformation, which lowers the fluid viscosity in this region. A scaling equation for electroosmotic mobility taking into account the non-Newtonian properties of polymer solutions is derived. It predicts electric field dependence of the electroosmotic mobility as the shear rate in the double layer is proportional to the electric field. Experimental measurements confirm the dependence of the electroosmotic mobility on the electric field.

Estimation of normal ranges for various biochemical parameters.

Frequency distributions of ten biochemical parameters are reported for a sample (40000 events) of the populations of Milano. Average values and standard deviations have been calculated for the female and male populations, subdivided in four classes of age. The values of the parameters increase with age; generally, except in the case of the rate of sedimentation, the values for the female population are lower with respect to those for the male population.