PubMed Health⌕ Search

Biomedical subjects

Guillermo Ayala

Publications and source records attributed to Guillermo Ayala.

3 recordsLinked to original sources

Suction catheter guided insertion of the ProSeal laryngeal mask airway is superior to the digital technique.

PURPOSE: We tested the hypothesis that digital insertion of the ProSeal laryngeal mask airway (ProSeal LMA) is more successful when using a suction catheter (SC) as a guide. METHODS: Two hundred and forty-three patients (ASA physical status I-III; aged 18-84 yr) were randomly allocated for the digital or SC-guided technique. The digital technique was performed according to the manufacturer's instructions. The SC technique involved priming the drain tube with the SC so that it protruded by 15 cm, blindly inserting the SC into the pharynx to a depth of 15 cm, followed by the digital technique. Failed insertion was defined by any of the following criteria: 1) failed passage into the pharynx; 2) malposition; and 3) ineffective ventilation. Any airway trauma, and visible or occult blood was noted. Sore throat, dysphonia and dysphagia were assessed 16 to 24 hr postoperatively. RESULTS: Fewer insertion attempts were required with the SC-guided technique (P = 0.02), but first attempt and overall success were similar. The time taken to provide an effective airway was shorter for the SC-guided technique (36 +/- 24 sec vs 44 +/- 28 sec, P = 0.02). A lateral approach was required less frequently with the SC-guided technique (0% vs 4%, P = 0.0004). There were no adverse events. Mouth trauma was more frequent with the digital technique (P = 0.04), but overall trauma was similar. There were no differences in the frequency of visible or occult blood. There were no differences in postoperative airway morbidity. CONCLUSIONS: The SC-guided technique is more frequently successful than the digital technique and is associated with less mouth trauma during insertion of the ProSeal LMA. We suggest that the SC technique may be a useful alternative when the digital technique fails.

Adolescent↗

Overlapping events with application to image sequences.

Counting spatially and temporally overlapping events in image sequences and estimating their shape-size and duration features are important issues in some applications. We propose a stochastic model, a particular case of the nonisotropic 3D Boolean model, for performing this analysis: the temporal Boolean model. Some probabilistic properties are derived and a methodology for parameter estimation from time-lapse image sequences is proposed using an explicit treatment of the temporal dimension. We estimate the mean number of germs per unit area and time, the mean grain size and the duration distribution. A wide simulation study in order to assess the proposed estimators showed promising results. The model was applied on biological image sequences of in-vivo cells in order to estimate new parameters such as the mean number and duration distribution of endocytic events. Our results show that the proposed temporal Boolean model is effective for obtaining information about dynamic processes which exhibit short-lived, but spatially and temporally overlapping events.

Algorithms↗

Spatio-temporal analysis of constitutive exocytosis in epithelial cells.

Exocytosis is an essential cellular trafficking process integral to the proper distribution and function of a plethora of molecules, including transporters, receptors, and enzymes. Moreover, incorrect protein targeting can lead to pathological conditions. Recently, the application of evanescent wave microscopy has allowed us to image the final steps of exocytosis. However, spatio-temporal analysis of fusion of constitutive vesicular traffic with the plasma membrane has not been systematically performed. Also, the spatial sites and times of vesicle fusion have not yet been analyzed together. In addition, more formal tests are required in testing biological hypotheses, rather than visual inspection combined with statistical descriptives. Ripley K-functions are used to examine the joint and marginal behavior of locations and fusion times. Semiautomatic detection and mapping of constitutive fusion sites reveals spatial and temporal clustering, but no dependency between the locations and times of fusion events. Our novel approach could be translated to other studies of membrane trafficking in health and diseases such as diabetes.

Cell Line↗