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At least 703 records · Page 39Linked to original sources
PubMed1995

The triple airway manoeuvre for insertion of the laryngeal mask airway in paralyzed patients.

The efficacy of the triple airway manoeuvre (mouth opening, head extension and jaw thrust) for insertion of the laryngeal mask airway (LMA) was compared with the standard insertion method. One hundred paralyzed patients were allocated randomly into two groups: in the control group (n = 50) the LMA was inserted by the standard method, and in the other (TAM group, n = 50) by the triple airway manoeuvre. In ten patients of each group, the position of the LMA and the epiglottis was assessed radiographically before insertion, after insertion but before cuff inflation, and after cuff inflation. In all patients the position was examined using fibrescopy before and after cuff inflation. The mean distance between the epiglottis and the posterior pharyngeal wall, measured radiographically before LMA insertion, was greater in the TAM group (16.3 (SD 4.3) mm) than in the control group (7.0 (2.8) mm) (P < 0.001). Before cuff inflation, radiography and fibrescopy showed that the LMA compressed the epiglottis downwards more frequently in the control group. After cuff inflation the glottis was completely visible fibreoptically in 66% in the TAM group, compared with 14% in the control group (P < 0.001). Complete downfolding of the epiglottis was seen in 10% in the control group and none in the TAM group (P < 0.05). We conclude that in paralyzed patients LMA insertion with the triple airway manoeuvre provides wider pharyngeal space and decreases the incidence of epiglottic downfolding by the LMA compared with the standard method.

Adult↗
PubMed1999

Laryngeal mask insertion using thiopental and low dose atracurium: a comparison with propofol.

PURPOSE: To compare the laryngeal mask airway (LMA) insertion conditions produced by propofol and a thiopental - low dose atracurium combination. METHODS: In a randomized controlled double blind study, 120 premedicated patients were allocated into four groups. After pre-oxygenation, anesthesia was induced as follows: 1 microg x kg(-1) fentanyl, 2.5 mg x kg(-1) propofol (group I); 1 microg x kg(-1) fentanyl, 5 mg x kg(-1) thiopental (group II); 1 microg x kg(-1) fentanyl, 5 mg x kg(-1) thiopental, 0.05 mg x kg(-1) or 0.1 mg x kg(-1) atracurium (groups III and IV respectively). The LMA was inserted by a blinded anesthesiologist who also assessed the following insertion conditions on a three point scale; jaw relaxation, biting, gagging, coughing, presence of laryngospasm, adequacy of airway patency, number of attempts at insertion and overall insertion conditions. RESULTS: There was no difference in insertion conditions between groups I, III and IV. Group II produced the worst overall conditions (P<0.05). There were no differences in hemodynamic changes and apnea times between all four groups. CONCLUSION: The combination of fentanyl-thiopental with low dose atracurium (0.05 or 0.1 mg x kg(-1)) provided conditions comparable with those of propofol for LMA insertion.

Adult↗
PubMed1994

[Jet ventilation superimposed on a special jet laryngoscope for endoluminal stent insertion in the tracheobronchial system].

BACKGROUND: Stenotic processes of the tracheobronchial system may lead to dyspnoea that can become lift-threatening. To restore sufficient function of the blocked airway, a silicone stent can be inserted. The anaesthesia techniques used for this intervention so far have been complicated. The object of this study was to determine whether the super-imposed high-frequency jet ventilation (SHFJV) via the jet laryngoscope originally designed for microlaryngeal surgery can be utilized for endoluminal stent insertion. METHODS: In 12 patients with acute respiratory insufficiency (ASA 3-5) due to stenosis of the tracheobronchial system, an endoluminal silicone stent was inserted through the jet laryngoscope while the patient was ventilated using SHFJV: RESULTS: A significant rise in paO2 readings prior to the jet ventilation and subsequent measurements was observed. The CO2 elimination was good (average paCO2 31.5 +/- 7.5-53.1 +/- 14 mmHg). Variably high paCO2 readings during stent insertion were related to the respective surgical phases. At the end of the surgical manipulation, all patients had sufficient spontaneous ventilation. CONCLUSIONS: First clinical applications of the jet laryngoscope combined with superimposed jet ventilation for stent insertion demonstrated satisfactory results. Not only were the patients ventilated throughout the procedure, but CO2 elimination was also satisfactory. Superimposed jet ventilation provides a sufficient tidal volume with low ventilation pressures, and therefore oxygenation and CO2 elimination are unproblematic. SHFJV enables the anaesthetist to ventilate the patient nearly continuously with minimal phases of apnoea. The only apnoea phases, as with any other method, occur during surgical manipulation while inserting the stent and thus blocking the airway. We believe that the jet laryngoscope with SHFJV presents a distinct advantage for both anaesthetist and surgeon when inserting stents in the tracheobronchial system.

Acute Disease↗
PubMed2006

Anatomical study of the femoral and tibial insertions of the anterolateral and posteromedial bundles of human posterior cruciate ligament.

For posterior cruciate ligament (PCL) reconstruction, two root, anterolateral and posteromedial bundles restruction are performed. However, little has been mentioned of anatomical measurements of the insertions to the bone of these bundles in previous publications. The aim of this study is to determine the precise anatomical measurements of the femoral and tibial insertions for anterolateral and posteromedial bundles of PCL. A total of 32 femur and 33 tibiae were selected from 50 cadavers after exclusion of knees that displayed macroscopically degenerative changes or evidence of trauma. PCL were divided into anterolateral bundles and posteromedial bundles to the insertion footprint, and those locations were measured and described. The distance from the center of the femoral insertions of the anterolateral and posteromedial bundles, and the Wrisberg ligament to the anterior margin of the medial femoral condyle averaged 9.6, 10.6, and 17.1 mm, respectively. The distance from the center of the femoral insertions of the anterolateral, posteromedial bundles, and Wrisberg ligament to the intercondylar roof averaged 4.8, 11.4, and 10.4 mm, respectively. The distance from the medial margin of the articular cartilage of the tibial plateau to the center of the tibial insertions of the anterolateral and posteromedial bundles averaged 51.0 and 50.0% of the total widest width of the tibial plateau, respectively. The vertical distance from the tibial insertion of the center of the posteromedial bundle to the plane of the tibial articular surface averaged 4.6 mm. This study leads to a better definition of the anatomy of the anterolateral and posteromedial bundles of PCL. It is very important to know the precise anatomy of PCL bundles when performing PCL reconstruction, and to evaluate PCL reconstruction surgery on an anatomical basis.

Cadaver↗
PubMed2000

Immunolocalization of types I, II, and X collagen in the tibial insertion sites of the medial meniscus.

The medial meniscus of the rabbit knee joint attaches to the tibial plateau via anterior and posterior insertions. Intact meniscal tibial insertions are essential for meniscal function. In the present study the distributions of types I, II, and X collagen in meniscal tibial insertions were investigated by indirect immunohistochemistry in a rabbit model. Four tissue zones were histologically identified in the anterior insertion site, including the ligamentous zone, uncalcified and calcified fibrocartilaginous zones and bone; the ligamentous zone was not observed in the posterior insertion site. Labeling for type I collagen was found to be strong in the ligament tissue and bone, and weak in the fibrocartilages which were also labeled for type II collagen. Tissues positive for different types of collagen overlapped and formed an irregular interface with various angles and depths, especially at the interface between the calcified fibrocartilage and bone. Positive labeling for type X collagen was identified only in the calcified fibrocartilage zone. The coexistence of types I and II collagen in the meniscal tibial insertions may indicate that this structural unit is subjected to both compressive and tensile loads. Type X collagen may play a role in maintaining the calcifying status of this tissue zone, so that its mechanical stiffness is kept between that of uncalcified fibrocartilage and hard bone. Restoration of the insertional structure including the distinct collagen distribution should be considered for a functional meniscal substitution.

Animals↗
PubMed2002

Characterization of a novel insertion sequence, IS Bp1, in Burkholderia pseudomallei.

During screening for antigenic proteins in Burkholderia pseudomallei, a novel insertion sequence, IS Bp1, was found by sequence similarity searches. IS Bp1 contains two overlapping ORFs of 261 bp ( orfA) and 852 bp ( orfB), encoding 87 and 284 amino acid residues, respectively, and an imperfect inverted repeat. The putative protein encoded by orfA (OrfA) is similar to the OrfA in insertion sequences of the IS 3 family in other bacteria, showing 49% and 76% amino acid identity and similarity, respectively, with the transposase encoded by IS D1 of Desulfovibrio vulgaris vulgaris. The putative protein encoded by orfB (OrfB) is similar to the OrfB in insertion sequences of the IS 3 family in other bacteria, showing 43% and 62% amino acid identity and similarity, respectively, with the transposase encoded by IS 1222 of Enterobacter agglomerans. Sequence analysis of OrfA showed the presence of an alpha-helix-turn-alpha-helix motif, as well as the putative leucine zipper at its 3' end, for possible DNA binding to the terminal inverted repeats. Sequence analysis of OrfB showed the presence of a DDE motif of aspartic acid, aspartic acid, and glutamic acid, a highly conserved motif present in OrfB of other members of the IS 3 family. Furthermore, several other conserved amino acid residues, including the arginine residue located seven amino acids downstream from the glutamic acid residue, were observed. PCR amplification of the IS Bp1 gene showed a specific band in 65% of the 26 B. pseudomallei strains tested. Southern blot hybridization after XhoI or SacI digestion showed nine different patterns of hybridization. The number of copies of IS Bp1 in those strains that possessed the insertion sequence ranged from three to 12. Using several insertion sequences and a combination of insertion-sequence-based and non-insertion-sequence-based methods such as ribotyping will probably increase the discriminatory power of molecular typing in B. pseudomallei.

Bacterial Proteins↗
PubMed2000

The driving force in trocar insertion: a comparison between disposable and reusable trocars.

BACKGROUND: Insertion of the first trocar during the "closed" technique of creating a pneumoperitoneum remains one of the most hazardous maneuvres in laparoscopic surgery, with complications such as major vascular and bowel injuries. The ease with which trocars are inserted through the abdominal wall may have some bearing on these complications. METHODS: A range of both disposable and reusable trocars, which were identical in point cross section and size, were compared in an abdominal wall model reconstructed with animal hide, using a hand-held pressure transducer. Multiple insertions were performed, and the results were expressed in pounds per square inch (PSI). RESULTS: The disposable trocar tested required the least effort to insert (mean pressure, 2.76 PSI), followed by the new reusable (mean pressure, 3.42 PSI), with the used reusable trocar requiring the greatest force for insertion (mean pressure, 4.80 PSI). CONCLUSIONS: The effect of previous use on ease of insertion demonstrates an obvious disadvantage of reusable instruments. The excessive force required to insert some trocars may place the patient at greater risk of trocar injury.

Abdominal Muscles↗
PubMed2005

Laryngeal mask airway can be inserted with inhaled desflurane induction.

PURPOSE: In this prospective, randomized, controlled trial, we investigated the reliability of laryngeal mask airway (LMA) insertion with inhaled desflurane. METHODS: Eighty patients undergoing elective surgery were randomized into two groups to receive either 2.5 mg x kg(-1) propofol (n = 40) or tidal breath desflurane (n = 40) induction followed by LMA insertion. All patients received fentanyl 1 microg x kg(-1) 2 min before induction. Inhalation of desflurane was started at 3% and increased by 3% every 3-5 breaths up to settings of 12%. RESULTS: Insertion of the LMA was faster in the propofol group (131.8 s versus 228.6 s, P < 0.01). The number of patients in whom the jaw opening was described as good (95% versus 72.5%, P = 0.27, for the desflurane and propofol groups, respectively) and the ease of LMA insertion described as good (87.5% versus 72.5%, P = 0.6) were comparable. The LMA was inserted in a single attempt in the majority of patients in both groups (80% versus 77.5%, P = 0.90). There were more complications at insertion in the propofol group than in the desflurane group (2.5% versus 19.5%, P < 0.01), especially for apnea (7.5% versus 70%, P < 0.01) and excitatory movements (2.5% versus 25%, P < 0.01). There were significant decreases in the mean arterial pressure in the propofol group compared to baseline data over the first 5 min of induction. Mean arterial pressure, heart rate, and S(p)(O2) remained stable during the same period in the desflurane group. CONCLUSION: We demonstrated that inhaled desflurane when used with caution in a controlled manner provided acceptable conditions for LMA insertion.

Desflurane↗
PubMed2006

In vitro cleaning efficacy and resistance to insertion test of interdental brushes.

The aim of this study was to compare the resistance to insertion forces and cleaning efficacy values of triangular interdental brushes (TIB) and conventional round interdental brushes (RIB). Extracted human teeth were fixed in a socket and matched to pairs simulating interdental spaces. Before and after standardized cleaning of the proximal surfaces, the pre- and postbrushing situations were registered with a digital camera. The cleaning efficacy was quantified by digital image subtraction. The forces necessary for insertion were measured with a load cell. The ratio between the relative cleaning efficacy and the forces necessary for insertion was calculated. The results of our study revealed that the relative cleaning efficacies of round and TIB were equal. There were no statistically significant differences. TIB showed significantly lower resistance to insertion values. Consequently, at identical resistance to insertion the TIB cleaned more effectively compared with the RIB, which means that the same effectiveness was reached by significantly lower forces at insertion. TIB showed a more favorable ratio between relative cleaning efficacy and resistance to insertion than RIB.

Dental Devices, Home Care↗
PubMed1985

Immediate post-placental IUD insertion: the expulsion problem.

This paper reports an evaluation of immediate post-placental insertion of a non-copper (Lippes Loop D) and several copper-bearing IUD models (TCu200, TCu220C, MLCu375, MLCu250, Nova T-PP, DimélysR). Based on the analysis of a total of 2,646 insertions and 55,794 woman-months of experience, we conclude that placement of an IUD within ten minutes of delivery of the placenta is a valuable alternative to interval insertion, because this method is safe and effective. Effectiveness was significantly lower for the Lippes Loop D than for the T- and ML-IUD models tested, the latter showing roughly comparable pertinent event rates. Pertinent event rates for copper IUDs were influenced by the skill of the operator; age of the recipient only had a significant effect on effectiveness, whereas parity had no significant effect on pertinent event rates. The single and still unsolved problem associated with immediate postpartum insertion is the greater likelihood of expulsion compared with interval insertion, and this hazard is significantly much greater for the Loop than for the copper-bearing devices assessed. The evolution of the expulsion rates shows a constant time-relationship. This pattern makes it obvious why follow-up of recipients, at least during the first trimester following insertion, is mandatory if immediate post-placental IUD insertion is to be optimally effective.

Adult↗
PubMed1989

Cervical laceration at IUD insertion--incidence and risk factors.

Incidence and risk factors of cervical laceration at IUD insertion are studied as the one remaining IUD insertion-related rare event using the multi-center IUD database developed by Family Health International. Two-hundred-ten lacerations were reported from 11,646 insertions (1.8 per 100 insertions) performed between 1977 and 1987. The incidence was twice as high in insertions with the copper devices and the multiload devices as in those with the Loop devices. Nulliparous women were found to be at an increased risk compared to multiparous women. Use of a tenaculum at insertion may also be a risk factor for laceration, but this finding needs to be confirmed by future studies. Data were not adequate to examine the effect of insertor's experience on the incidence of cervical lacerations at insertion.

Adult↗
PubMed1986

Regeneration of transected rat sciatic nerves after using isolated nerve fragments as distal inserts in silicone tubes.

We determined blood vessel and perineurial fascicle densities as well as axonal numbers in regenerated rat sciatic nerves 8 weeks after the nerves had been transected, the proximal stumps placed into the proximal ends of silicone tubes, and isolated fragments of nerve placed into the distal ends of the same tubes. The data are compared with data from the normal nerve and from regeneration in a similar paradigm in which the distal stumps were used as the inserts into the distal end of the silicone tubes. A major difference between the two regeneration paradigms was that axons were discouraged from reaching the periphery when the distal insert was an isolated fragment and encouraged to reach the periphery when the distal insert was the distal stump. We found that fascicle and blood vessel densities were greater than normal but less than with the distal stump as the distal insert. Thus we concluded that the nature of the distal insert had a bearing on how many vessels and perineurial fascicles were formed during regeneration in these conditions. Myelinated axon numbers did not differ in the two conditions whereas there were more unmyelinated axons with the isolated distal stump as the distal insert. Thus at this regeneration time the numbers of myelinated axons were not as dependent on the nature of the distal insert as were the numbers of unmyelinated axons. Finally the length of the gap had a great influence on the numbers of axons that regenerated.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Identification and nucleotide sequence of the regions of Autographa californica nuclear polyhedrosis virus genome carrying insertion elements derived from Spodoptera frugiperda.

A morphology mutant of the baculovirus Autographa californica nuclear polyhedrosis virus called M5 was previously shown to synthesize two size classes of viral DNA, one of which had a deletion of 42% of the genome. It was hypothesized that the presence of the smaller M5 circular DNA resulted from the specific deletion of the region located between two sites carrying short DNA insertions. These sites have now been identified by DNA-DNA hybridization using cloned EcoRI fragments of M5 DNA. One cloned M5 EcoRI fragment was found to correspond to the deletion junction fragment where sequences from the insertion site in the 2.6-map unit region were covalently linked to sequences from the insertion site in the 46-map unit region. The 2.6- and 46-map unit regions of Wt AcMNPV DNA were sequenced. Potential long open reading frames which would be disrupted by the M5 inserts were detected. Nucleotide sequence analysis of the same regions of M5 DNA revealed the presence of almost identical inserts of 290 bp. The primary sequence of the inserts revealed characteristics similar to the termini of transposons. Hybridization studies suggested that the inserts were derived from repetitive elements of the Spodoptera frugiperda host cell genome.

Animals↗
PubMed1978

IS1 insertion generates duplication of a nine base pair sequence at its target site.

Three independent integrations of the E. coli insertion sequence, IS1, into the gal operon have been analyzed. DNA sequences of portions of the wild-type galT gene which act as the target sites for these insertions, as well as the corresponding gal/IS1 junctions, are reported. Two features are particularly noteworthy. First, similar sequences appearing in inverted orientation consitute the ends of IS1: 18 of the terminal 23 base pairs at each end are identical. Second, in all three insertions, a 9 base pair segment found once in the wild-type sequence at the site of insertion is duplicated and appears in the same orientation at each end of the inserted element. The sequence of this 9 base pair repeat is different for each insertion analyzed. No homology between the inverted repeat sequences at the ends of IS1 and the sequences of the target sites is observed. Models for the mechanism of IS1 insertion are proposed.

Base Sequence↗
PubMed1980

Insertions of Tn 10 into an E. coli ribosomal RNA operon are incompletely polar.

Insertions of the transposon Tn 10 have been obtained in an E. coli ribosomal RNA operon (rrnX). These insertions were used to determine whether present models of polarity are sufficient to explain transcriptional properties of operon which are transcribed but not translated. Most models of polarity suggest that transcription of mRNA requires simultaneous translation of nascent mRNA, or else premature termination of transcription will result. This model as stated does not encompass rrn operons. In this study three Tn 10 insertions into rrnX were characterized. All three Tn 10 insertions do not completely eliminate in vivo transcription of the most distal tRNA gene of rrnX. In ultraviolet-irradiated cells one Tn 10 insertion reduces synthesis of downstream portions of rrnX by at most 2--3 fold. Two other insertions may have more extensive polar effects, although the exact level of polarity is difficult to evaluate because these Tn 10 insertions may affect RNA maturation and stability.

DNA Transposable Elements↗
PubMed1981

Retroviruses as mutagens: insertion and excision of a nontransforming provirus alter expression of a resident transforming provirus.

Integration of retroviral DNA appears to occur randomly in host genomes, suggesting that retroviruses can act as insertion mutagens. We have confirmed this prediction by showing that the nontransforming retrovirus, Moloney murine leukemia virus (M-MuLV), can insert its provirus within the selectable target provided by a single provirus in a clonal rat cell line (B31) transformed by Rous sarcoma virus (RSV). Analysis of over 60 morphological revertants of M-MuLV-superinfected B31 cells revealed two lines with inserts of M-MuLV proviruses within the RSV provirus but outside the transforming gene of RSV (src), at sites 0.6 and 4.0 kb from the 5' end. The inserts did not inactivate initiation of RSV RNA synthesis but did affect elongation or processing, or both, generating species with the 5' end of RSV RNA linked to sequences that presumably derive from the inserted M-MuLV DNA. In one mutant line, most of the insert was excised at low frequency, apparently by homologous recombination between repeated sequences at the ends of M-MuLV DNA. After excision, RSV src mRNA was present in normal amounts, and the cells resumed a transformed appearance. In at least four independent lines, large portions of the left end of the RSV provirus (from 1 to 6 kb) and variable amounts of leftward flanking cellular DNA (from 0.5 to 10-15 kb or more) were deleted, without nearby insertions of M-MuLV NA. The deletions removed the putative promoter for synthesis of RSV RNA; in the two cases examined, no RSV RNA was detected. These deletions may represent a second mutational effect of the superinfection by M-MuLV.

Animals↗
PubMed1985

Tn5 insertions in the agrocin 84 plasmid: the conjugal nature of pAgK84 and the locations of determinants for transfer and agrocin 84 production.

The kanamycin-resistance transposon Tn5 was randomly introduced into pAgK84, a 47.7-kb plasmid coding for agrocin 84 production in Agrobacterium. Using such marked plasmids, pAgK84 was found to be conjugal. It could be transferred to several Agrobacterium strains including those harboring octopine- or nopaline-type Ti plasmids. Its presence has no effect on Ti plasmid functions such as opine utilization and tumorigenicity, but it does confer agrocin 84 immunity upon previously sensitive strains. The plasmid could also be conjugally transferred to a Nod+ Fix+ strain of Rhizobium meliloti. The production of agrocin 84 is expressed in all Agrobacterium and Rhizobium transconjugants tested. The agrocin plasmid could not be introduced into restrictionless Escherichia coli or Pseudomonas aeruginosa recipients by conjugation or transformation. The sites of 92 independent Tn5 insertions were mapped on pAgK84. These insertions are dispersed over the entire length of the plasmid. Analysis of the sites and effects of the Tn5 insertions has allowed us to construct a functional map of pAgK84. Forty-three of these insertions, spanning a 20-kb segment of the plasmid, abolished or greatly reduced the production of agrocin 84. The presence of two insertions within this segment having an effect on agrocin production suggests that at least three regions of the plasmid are involved in agrocin 84 biosynthesis. Fourteen of the Tn5 insertion derivatives are no longer conjugally transferable. These insertions all map to a single region of the plasmid and define about 3.5-kb as being associated with transfer functions.

Adenine Nucleotides↗
PubMed1992

Three-dimensional theoretical temperature distributions produced by 915 MHz dipole antenna arrays with varying insertion depths in muscle tissue.

Interstitial microwave antenna array hyperthermia (IMAAH) systems are currently being used in the treatment of cancer. The insertion depth of an interstitial microwave antenna, defined as the length of the antenna from the tip to the point of insertion in tissue, affects its ability to produce uniform power deposition patterns in tumor volumes. The effect of varying insertion depths on the ability of an IMAAH system to heat two theoretical tumor models was examined. Four dipole microwave antennas were implanted in a 2 x 2 cm array and driven at 915 MHz in muscle tissue. The explicit power deposition patterns were calculated for each insertion depth using known theory. The bioheat transfer equation was solved for the 3-dimensional steady-state temperature distributions in cylindrical and ellipsoidal tumor models using a finite element method. Homogeneous and nonhomogeneous blood flow models were considered. As a basis of comparison of the various temperature distributions, the volume of tumor heated to greater than or equal to 43 degrees C was calculated. Under the conditions of this study, the insertion depth was shown to have a significant effect on the ability of an IMAAH system to heat the tumor volumes. A sharp decrease in the percentage of tumor volume heated to greater than or equal to 43 degrees C was seen for insertion depths between 7.8 and 14.6 cm. At an insertion depth of 11.7 cm (3/4 lambda) there was virtually no heating of the tumor. Regions of elevated power occurred outside of the desired treatment volume, stressing the importance of adequate thermometry techniques and demonstrating the need for hyperthermia treatment planning prior to implantation of an antenna array. Plots of the power deposition patterns and the corresponding temperatures produced in the diagonal plane of the antenna arrays are present.

Equipment Design↗