Acoustic rhinometry to evaluate plastic surgery results of the nasal septum.

UNLABELLED: Acoustic rhinometry to evaluate plastic surgery results of the nasal septum. OBJECTIVE: In this study, acoustic rhinometry was used in the preoperative and postoperative evaluation of 16 patients undergoing surgery for nasal obstruction. METHODOLOGY: The parameters evaluated prior to and subsequent to the operation were the diameter of the nasal cavity at its narrowest point, and the total volume of the nasal cavity. RESULTS: This method accurately showed changes in the dimensions of the nasal cavity following surgery. As shown by acoustic rhinometry, the change in the mean minimal cross-sectional area of the nasal cavity was 67%. Similarly, the augmentation of the mean total volume of the nasal cavity was 24.15%. The change in the dimensions of the nasal cavity paralleled the improvement in clinical symptoms. CONCLUSION: Acoustic rhinometry can accurately measure the dimensions of the nasal cavity, especially at the front part. It can also be used to assess the efficiency of treatment in cases of nasal obstruction, especially plastic surgery of the nasal septum.

Decannulation in children after long-term tracheostomy.

Various approaches and techniques are used in discontinuing tracheostomy in children. The variability in the use of resources is considerable. The objective of the study was to assess decannulation in children attending our ENT department. A retrospective analysis was carried out of the medical records of patients who had had both a tracheostomy (n=7) and a decannulation (n=6) from 1998 to 2003. Tracheostomies placed at a mean age of 4.2 months were discontinued on average 26.4 months later. All the children underwent airway endoscopy in the operating room in preparation for decannulation. They had downsizing, then capping of the tracheostomy as a functional trial. One child failed decannulation and another needed a second trial for successful decannulation. The individualization of tracheostomy decannulation is necessary in children.

In vitro cultivation of Trypanoplasma borreli (protozoa: kinetoplastida), a parasite from the blood of common carp Cyprinus carpio.

An in vitro culture system was developed for Trypanoplasma borreli, a pathogenic flagellate from the blood of European cyprinids. Trypanoplasms multiplied rapidly in a mixture of Hanks' balanced salt solution (HBSS, 45%), L15 (22.5%), Earle's minimum essential medium (MEM, 22.5%) and 10% distilled water, which was supplemented with 5 to 10% heat-inactivated pooled carp serum. In medium supplemented with fetal bovine serum, multiplication of T. borreli seemed to be inhibited. Cultures initiated with less than 100 000 T. borreli per ml culture medium did not survive, and a substantial multiplication of trypanoplasms was found at inocula beginning with 630 000 flagellates ml(-1). Trypanoplasms multiplied at 15, 20 and 25 degrees C. In cultures incubated at 4 degrees C the trypanoplasms remained viable but the number of flagellates did not increase. Trypanoplasms from in vitro cultures retained their infectivity for carp for at least 90 d (5 passages). The trypanoplasms survived in culture over a period of up to 5 mo (10 passages). The established culture system allows the propagation of high numbers of fish-infective trypanoplasms, which are required to study parasite-host relationships in carp.

Noisy neural nets exhibiting memory domains.

Previous studies with probabilistic neural nets in which the neural connections are set up by means of chemical markers, revealed the existence of multiple memory domains. We generalized these studies by considering the intrinsic noise of the systems, caused by the spontaneous release of synaptic transmitter substance. A simple mathematical model is developed, which yields characteristics of multiple memory domains analogous to those occurring in noiseless nets.

A computer model for learning processes and the role of the cerebral commissures.

A computer model of the two brain hemispheres is constructed of discrete populations of neurons, and it is shown to exhibit the characteristics of the great cerebral commissures, as has been pointed out by Sperry and others. For the range of parameters used we find that such systems respond in a specific manner to specific stimuli, and furthermore, whatever memory is transferred to one simulated hemisphere is also transferred to the other. However, this behavior changes when the two hemispheres are separated. We find that memory is not transferred from one hemisphere to the other when the interconnecting commissures are severed. The above findings verify Sperry's experimental observation that the split brain behaves as if it were indeed two separate brains, each performing concurrently and simultaneously diametrically opposite tasks.