Search results for "RESPIRATORY SYSTEM"
showing 10 items of 1829 documents
High mitochondrial DNA sequence diversity in the parthenogenetic earthworm Dendrobaena octaedra
2010
Apomictic parthenogens are clonal organisms with limited genetic opportunity for increasing diversity beyond mutation. However, such species can be successful and have been shown to harbor more genetic diversity than might be expected. Here we surveyed diversity of the cytochrome oxidase subunit I gene from the mitochondrial genome of the earthworm Dendrobaena octaedra, an apomictic parthenogen. Diversity estimates made previously from allozyme markers for this species were high, but could have been affected by a detection bias, namely variable expression of alleles in the polyploid genome. We found similarly high mtDNA diversity over three localities in Finland, each represented by two sit…
Computational analysis of lung deformation after murine pneumonectomy. [corrected].
2012
In many mammalian species, the removal of one lung (pneumonectomy) is associated with the compensatory growth of the remaining lung. To investigate the hypothesis that parenchymal deformation may trigger lung regeneration, we used microCT scanning to create 3-dimensional finite element geometric models of the murine lung pre- and post-pneumonectomy (24 hours). The structural correspondence between models was established using anatomic landmarks and an iterative computational algorithm. When compared with the pre-pneumonectomy lung, the post-pneumonectomy models demonstrated significant translation and rotation of the cardiac lobe into the post-pneumonectomy pleural space. 2-dimensional maps…
Synthetic Pulmonary Surfactant Preparations: New developments and future trends
2008
Pulmonary surfactant is a lipid-protein complex that coats the interior of the alveoli and enables the lungs to function properly. Upon its synthesis, lung surfactant adsorbs at the interface between the air and the hypophase, a capillary aqueous layer covering the alveoli. By lowering and modulating surface tension during breathing, lung surfactant reduces respiratory work of expansion, and stabilises alveoli against collapse during expiration. Pulmonary surfactant deficiency, or dysfunction, contributes to several respiratory pathologies, such as infant respiratory distress syndrome (IRDS) in premature neonates, and acute respiratory distress syndrome (ARDS) in children and adults. The ma…
Construction of a dual chain pseudotetrameric chicken avidin by combining two circularly permuted avidins.
2004
Two distinct circularly permuted forms of chicken avidin were designed with the aim of constructing a fusion avidin containing two biotin-binding sites in one polypeptide. The old N and C termini of wild-type avidin were connected to each other via a glycine/serine-rich linker, and the new termini were introduced into two different loops. This enabled the creation of the desired fusion construct using a short linker peptide between the two different circularly permuted subunits. The circularly permuted avidins (circularly permuted avidin 5 → 4 and circularly permuted avidin 6 → 5) and their fusion, pseudotetrameric dual chain avidin, were biologically active, i.e. showed biotin binding, and…
Diagnostic accuracy of cone-beam CT compared with panoramic images in predicting retromolar canal during extraction of impacted mandibular third mola…
2014
Objectives: The clinical significance of the existence of a retromolar canal and of its neurovascular content is not yet clear.The aim of the present study was to assess the visibility, diameter and course of the mandibular retromolarcanal (MRC) using cone beam computed tomography (CBCT) scan -had been taken for pre-operative radiographic evaluation of impacted mandibular third molars- compared to panoramic radiographs. Study Design: Subjects eligible for study enrollment were those who underwent preoperative CBCT scan for the extraction of impactedmandibular third molars were determined to be extremely close to the mandibular canal on panoramic radiographs. Radiographs were screened for th…
Marginal bone loss in the second molar related to impacted mandibular third molars : comparison between panoramic images and cone beam computed tomog…
2020
Background Deciding whether or not to extract third molars remains a controversial situation in dental practice. Image exams support this decision by enabling a close view of the third molar, its adjacent bone and its relationship with the second molar. This study aimed to assess and compare second molar bone loss adjacent to impacted mandibular third molar in panoramic radiographs (PAN) and cone beam computed tomography (CBCT) scans. Material and Methods A sample of 70 patients was selected (n=124 teeth). Each patient had a set of a panoramic radiograph and CBCT scans consecutively taken for dental treatment purposes. In PAN and CBCT, mandibular third molars were classified based on their …
Differences between panoramic and Cone Beam-CT in the surgical evaluation of lower third molars
2017
Background The aim of this study was to evaluate the ability to identify the contiguity between the root of the mandibular third molar and the mandibular canal (MC) in panoramic radiographs compared with Cone Beam-CT. Material and methods Panoramic radiographs of 326 third molars and CBCT radiographs of 86 cases indicated for surgery and considered at risk were evaluated. The following signs were assessed in panoramic radiographs as risk factors: radiolucent band, loss of MC border, change in MC direction, MC narrowing, root narrowing, root deviation, bifid apex, superimposition, and contact between the root third molar and the MC. Results Radiographic signs associated with absence of MC co…
Radiographic signs associated with inferior alveolar nerve damage following lower third molar extraction
2009
The aim was to carry out a literature review of preoperative radiographic signs in orthopantomography (OPG) and computed tomography (CT) related with the risk of inferior alveolar nerve damage during the surgical extraction of lower third molar (LTM). A search was made on PubMed for literature published between the years 2000 and 2009. In the reviewed literature, radiographic signs in the OPG that indicate a relationship between the LTM and the inferior alveolar canal are considered a risk factor for nerve damage. These signs are darkening and deflection of the root, and diversion and interruption in the white line of the canal. In the majority of these studies, the routine use of CT is not…
Acquired C1 inhibitor (C1-INH) deficiency type II. Replacement therapy with C1-INH and analysis of patients' C1-INH and anti-C1-INH autoantibodies
1989
Abstract The response of two patients with autoantibody-mediated C1-inhibitor (C1-INH) deficiency to replacement therapy with C1-INH was studied over a period of 3 d. In patient 1 an acute attack of angioedema was successfully managed by infusion of 1,000 U of C1-INH concentrate. C1-INH function returned to normal levels within 30 min, while CH50 and C4 peaked after 6-7 h and C1 hemolytic activity reached 50-60% of normal after 3 d. Immediately after the injection an increase in C1-INH-anti-C1-INH complexes was observed. Based on NH2-terminal sequence analysis of the patients' Mr 96,000 C1-INH, it is concluded that this fragment is generated after cleavage of C1-INH in its active site by on…
Spatial distribution of various types of bulbar respiratory neurons in the rabbit
1977
In anesthetized rabbits, the burst activity of 277 single respiratory neurons was recorded extracellularly. The neurons were classified according to their spike incidence distribution within the respiratory cycle and to their response to lung distension or collapse (alpha or beta type). About one third of the neurons found in all animals were located at the level of the caudal end of the promontorium gliosum, widely scattered over the bulbar cross-section. More rostrally the units were located within a dorsal area neighbouring the tractus solitarius, more caudally within a ventral field surrounding the nucleus ambiguus. Most of the inspiratory neurons (the most frequently encountered type) …