MANUAL JET VENTILATION V. HIGH FREQUENCY JET VENTILATION DURING LASER RESECTION OF TRACHEO-BRONCHIAL STENOSIS

SUMMARY Manual jet ventilation (20 b.p.m.) and high frequency jet ventilation (300 b.p.m.) were compared during laser resection of tracheo-bronchial stenosis under general anaesthesia. Both methods provided similar blood-gas tension* at the 10th min of surgery in patients with tracheal stenosis. In patients with bronchial stenosis high frequency jet ventilation resulted in modest hypercarbia and manual jet ventilation appeared to be the pretexted method in these particular patients. Although high frequency jet ventilation has been used experimentally PATIENTS AND METHODS Patients Forty patients with severe airway stenosis were studied during laser photoresection. The method of ventilation was HFJV (300 b.p.m.) in the first group of 20 patients and manual JV (20 b.p.m.) in the second group. Twenty-three patients presented with tracheal stenosis (13 in the HFJV group, 10 in the JV group) and 17 with stenosis of a main bronchus (seven in the HFJV group, 10 in the JV group). Methods Anaesthesia and bronchoscopic technique were as described previously (Vourc'h et al., 1983). The tip of the bronchoscope was kept just above the stenosis, either in the trachea or in a main bronchus. In this latter instance, ventilation of the contralateral lung was provided through side vents (Jardine, Harrisson and Healy, 1975). Statistical analysis Results were expressed as the mean ± standard deviation. Statistical analysis used Student's ftest for comparison between the two groups of patients; A probability of P< 0.05 was regarded as statistically significant. RESULTS The results are summarized in table I. Blood-gas tensions were similar in the two groups before anaesthesia; 10 min following the beginning of surgery Pao? did not differ but PacOj was greater in the HFJV group (5.43 ± 1.76 kPa) than in the JV group (4.34 ± 0.9 kPa)(P< 0.02). Comparison between the two types of ventilation in patients with tracheal stenosis showed no differenc

Analysis and Design of a Compact Leaky-Wave Antenna for Wide-Band Broadside Radiation

A low-cost compact planar leaky-wave antenna (LWA) is proposed offering directive broadside radiation over a significantly wide bandwidth. The design is based on an annular metallic strip grating (MSG) configuration, placed on top of a dual-layer grounded dielectric substrate. This defines a new two-layer parallel-plate open waveguide, whose operational principles are accurately investigated. To assist in our antenna design, a method-of-moments dispersion analysis has been developed to characterize the relevant TM and TE modes of the perturbed guiding structure. By proper selection of the MSG for a fabricated prototype and its supporting dielectric layers as well as the practical TM antenna feed embedded in the bottom ground plane, far-field pencil-beam patterns are observed at broadside and over a wide frequency range, i.e., from 21.9 GHz to 23.9 GHz, defining a radiating percentage bandwidth of more than 8.5%. This can be explained by a dominantly excited TM mode, with low dispersion, employed to generate a two-sided far-field beam pattern which combines to produce a single beam at broadside over frequency. Some applications of this planar antenna include radar and satellite communications at microwave and millimeter-wave frequencies as well as future 5G communication devices and wireless power transmission systems

Genome-wide Analyses Identify KIF5A as a Novel ALS Gene

To identify novel genes associated with ALS, we undertook two lines of investigation. We carried out a genome-wide association study comparing 20,806 ALS cases and 59,804 controls. Independently, we performed a rare variant burden analysis comparing 1,138 index familial ALS cases and 19,494 controls. Through both approaches, we identified kinesin family member 5A (KIF5A) as a novel gene associated with ALS. Interestingly, mutations predominantly in the N-terminal motor domain of KIF5A are causative for two neurodegenerative diseases: hereditary spastic paraplegia (SPG10) and Charcot-Marie-Tooth type 2 (CMT2). In contrast, ALS-associated mutations are primarily located at the C-terminal cargo-binding tail domain and patients harboring loss-of-function mutations displayed an extended survival relative to typical ALS cases. Taken together, these results broaden the phenotype spectrum resulting from mutations in KIF5A and strengthen the role of cytoskeletal defects in the pathogenesis of ALS.Peer reviewe

The acetylcholinesterase gene ACE : a diagnostic marker for the pipiens and quinquefasciatus forms of the Culex pipiens complex

The taxonomy of the #Culex pipiens complex remains a controversial issue in mosquito systematics. Based on morphologic characters, 2 allopatric taxa are recognized, namely #Cx. pipiens (including the form "#molestus") in temperate areas and #Cx. quinquefasciatus in tropical areas. Here we report on variability at nucleotide level of an acetylcholinesterase gene in several strains and natural populations of this species complex. Few polymorphisms were found in coding regions within a subspecies but many polymorphisms were observed between subspecies in noncoding regions. We describe a method based on a restriction enzyme polymorphism in polmerase chain reaction-amplified DNA, in which the presence or absence of one restriction site discriminates #Cx. pipiens, #Cx. quinquefasciatus, and their hybrids. This technique reliably discriminates mosquitoes from more than 30 worldwide strains or populations. Polymerase chain reaction amplification of specific alleles may also be a useful tool for characterizing specific alleles of each sibling taxon. (Résumé d'auteur