The relevance of threaded external skeletal fixation pin insertion speed in canine bone with and without predrilling

2014 ◽  
Vol 27 (04) ◽  
pp. 249-256 ◽  
Author(s):  
M. C. Rochat ◽  
T. A. Snider ◽  
M. E. Payton ◽  
J. T. Walker
Keyword(s):  
Temperature Increase ◽  
Null Hypothesis ◽  
Thermal Damage ◽  
Insertion Site ◽  
Maximum Temperature ◽  
Minimal Effect ◽  
Thermal Necrosis ◽  
Pilot Hole ◽  
Damage Data ◽  
Insertion Sites

SummaryObjectives: The effects of insertion speed in revolutions per minute (RPM) and pilot hole predrilling for placement of threaded external skeletal fixation pins on temperature and morphological damage in cortical bone were evaluated. The null hypothesis states that insertion speed and predrilling will have no significant effect on temperature and morphological damage.Methods: Fixation pins were inserted into cadaveric canine femurs at speeds of 700 RPM and 150 RPM, with and without predrilling. Temperature was measured at each cortex 0.5 mm and 3.0 mm from each insertion site. Samples were examined grossly and by scanning electron microscopy for evidence of morphological damage. Data were analysed for maximum temperature, temperature increase, sites above thermal necrosis thresholds, microcracks, thread quality and gross damage.Results: Predrilling had a significant effect on maximum temperature, temperature increase, sites exceeding necrosis thresholds, microcracks, thread quality and gross damage. Speed of insertion had no significant effect on any of the measured parameters following predrilling, but had a significant effect on thread quality without predrilling.Clinical significance: Our results fail to reject the null hypothesis concerning insertion speed, which had no significant effect on thermal damage, and minimal effect on morphological damage, which was negated by predrilling. Our results reject the null hypothesis concerning predrilling and support the practice of predrilling fixation pin insertion sites.

scholarly journals Tn5406, a New Staphylococcal Transposon Conferring Resistance to Streptogramin A and Related Compounds Including Dalfopristin

2002 ◽  
Vol 46 (8) ◽  
pp. 2337-2343 ◽  
Author(s):  
Julien Haroche ◽  
Jeanine Allignet ◽  
Névine El Solh
Keyword(s):  
Staphylococcus Aureus ◽  
Insertion Site ◽  
Single Copy ◽  
Amino Acid Identity ◽  
Plasmid Copy ◽  
Acid Identity ◽  
Abc Protein ◽  
Single Plasmid ◽  
Insertion Sites ◽  
Related Compounds

ABSTRACT We characterized a new transposon, Tn5406 (5,467 bp), in a clinical isolate of Staphylococcus aureus (BM3327). It carries a variant of vgaA, which encodes a putative ABC protein conferring resistance to streptogramin A but not to mixtures of streptogramins A and B. It also carries three putative genes, the products of which exhibit significant similarities (61 to 73% amino acid identity) to the three transposases of the staphylococcal transposon Tn554. Like Tn554, Tn5406 failed to generate target repeats. In BM3327, the single copy of Tn5406 was inserted into the chromosomal att554 site, which is the preferential insertion site of Tn554. In three other independent S. aureus clinical isolates, Tn5406 was either present as a single plasmid copy (BM3318), as two chromosomal copies (BM3252), or both in the chromosome and on a plasmid (BM3385). The Tn5406-carrying plasmids also contain two other genes, vgaB and vatB. The insertion sites of Tn5406 in BM3252 were studied: one copy was in att554, and one copy was in the additional SCCmec element. Amplification experiments revealed circular forms of Tn5406, indicating that this transposon might be active. To our knowledge, a transposon conferring resistance to streptogramin A and related compounds has not been previously described.

A comparison of transparent polyurethane and dry gauze dressings for peripheral i.v. catheter sites: rates of phlebitis, infiltration, and dislodgment by patients

1997 ◽  
Vol 6 (5) ◽  
pp. 377-381 ◽  
Author(s):  
KA Tripepi-Bova ◽  
KD Woods ◽  
MC Loach
Keyword(s):  
Direct Observation ◽  
Meta Analysis ◽  
Insertion Site ◽  
Direct Visualization ◽  
Gauze Dressing ◽  
Insertion Sites ◽  
To Receive ◽  
Lower Frequencies

BACKGROUND: Before a meta-analysis by Hoffman et al was published, polyurethane dressings were used at insertion sites for peripheral i.v. catheters at our institution. On the basis of the results of the meta-analysis, we began to use gauze dressings. The change from polyurethane dressings to gauze dressings limited direct observation of the i.v. insertion site, and i.v. catheters were anecdotally reported not to be anchored as securely as before. OBJECTIVES: The purpose of this study was to compare the effects of the use of transparent polyurethane dressings and gauze dressings at insertion sites for peripheral i.v. catheters on the frequency of phlebitis, infiltration, and catheter dislodgment by patients. METHODS: Two hundred twenty-nine patients were randomized to receive either gauze (n = 121) or transparent polyurethane (n = 108) dressings, and observations were recorded. RESULTS: The frequency of catheter dislodgment by the patient was significantly higher (P < .05) in patients with the gauze dressing (15%) than in patients with the transparent polyurethane dressing (6%). A trend toward lower frequencies of phlebitis (1.8% vs 3.3%) and infiltration (17.6% vs 20.7%) was noted in the patients with the transparent polyurethane dressings. DISCUSSION: The clinical advantages of the transparent polyurethane dressings lie in the ease of direct visualization of the i.v. insertion site and the securement of the i.v. catheter. CONCLUSION: At our institution, given the decreased disruption of the i.v. therapy with the transparent polyurethane dressings and the lack of differences in the rates of phlebitis or infiltration with the two types of dressings, we prefer to use transparent polyurethane rather than gauze dressings at insertion sites for peripheral i.v. catheters.

Patency of radial arterial catheters

2001 ◽  
Vol 10 (2) ◽  
pp. 104-111 ◽  
Author(s):  
J Kaye ◽  
GR Heald ◽  
J Morton ◽  
T Weaver
Keyword(s):  
Sampling Methods ◽  
Insertion Site ◽  
Blood Sampling ◽  
Monitoring Systems ◽  
Site Location ◽  
Pressure Monitoring ◽  
Radiocarpal Joint ◽  
Background Data ◽  
Isotonic Sodium Chloride ◽  
Insertion Sites

BACKGROUND: Data on the influence of flush methods, blood-sampling methods, and site location on the patency of radial arterial catheters used for pressure monitoring are sparse. OBJECTIVES: To determine the effects of flush and blood-sampling methods, insertion site, and sex of patients on catheter patency. METHODS: In a randomized trial, 174 patients requiring radial arterial pressure monitoring were assigned to 4 groups: fast flush as needed and nonwaste blood sampling; fast flush as needed and waste blood sampling; fast flush every 4 hours and waste blood sampling; and fast flush every 4 hours and nonwaste blood sampling. All site locations were evaluated for patency, and all monitoring systems were maintained with isotonic sodium chloride solution. RESULTS: Nonpatent catheters were 4.23 times more likely in patients with insertion sites 3 cm or higher above the bend of the wrist than in patients with lower sites (P = .01). Duration of patency did not differ between catheters maintained with fast flush every 4 hours and those flushed as needed or between catheters according to the method of blood sampling. Women were 3.05 times more likely than men to have nonpatent catheters (P = .02). With insertion sites 3 cm or higher above the radiocarpal joint, nonpatency was 7.3 times more likely in women than in men (P < .001). CONCLUSIONS: Insertion sites closest to the bend of the wrist increase chances of maintaining patency. Catheters can be maintained with as-needed flushes, and either waste or nonwaste blood sampling can be used.

scholarly journals Assessment of Effects of Laser Light Combining Three Wavelengths (450, 520 and 640 nm) on Temperature Increase and Depth of Tissue Lesions in an Ex Vivo Study

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5340
Author(s):  
Kamil Jurczyszyn ◽  
Witold Trzeciakowski ◽  
Zdzisław Woźniak ◽  
Piotr Ziółkowski ◽  
Mateusz Trafalski
Keyword(s):  
Duty Cycle ◽  
Temperature Increase ◽  
Ex Vivo ◽  
Visible Spectrum ◽  
Maximum Temperature ◽  
Lesion Depth ◽  
Single Beam ◽  
Duty Cycles ◽  
Rate Of Increase

Background: Lasers are widely used in medicine in soft and hard tissue surgeries and biostimulation. Studies found in literature typically compare the effects of single-wavelength lasers on tissues or cell cultures. In our study, we used a diode laser capable of emitting three components of visible light (640 nm, red; 520 nm, green; 450 nm, blue) and combining them in a single beam. The aim of the study was to assess the effects of laser radiation in the visible spectrum on tissue in vitro, depending on the wavelength and pulse width. Methods: All irradiations were performed using the same output power (1.5 W). We used various duty cycles: 10, 50, 80 and 100% with 100 Hz frequency. Maximum superficial temperature, rate of temperature increase and lesion depth were investigated. Results: Maximum superficial temperature was observed for 450 + 520 nm irradiation (100% duty cycle). The highest rate of increase of temperature was noted for 450 + 520 nm (100% duty cycle). Maximum lesion depth was observed in case of three-wavelength irradiation (450 + 520 + 640 nm) for 100, 80 and 50% duty cycles. Conclusions: The synergistic effect of two-wavelength (450 + 520 nm) irradiation was observed in case of maximum temperature measurement. The deepest depth of lesion was noted after three-wavelength irradiation (450 + 520 + 640 nm).

Airbag deployment: Infrared thermography and evaluation of thermal damage

2019 ◽  
Vol 233 (4) ◽  
pp. 424-431 ◽  
Author(s):  
Ehsan Shakouri ◽  
Alimohammad Mobini
Keyword(s):  
Infrared Thermography ◽  
Chemical Reaction ◽  
Direct Contact ◽  
Thermal Damage ◽  
Maximum Temperature ◽  
Time Intervals ◽  
Hot Gas ◽  
Exothermic Chemical Reaction ◽  
Zero Moment ◽  
Airbag Deployment

The performance of airbag and its deployment are based on a fast exothermic-chemical reaction. The hot gas resulting from the chemical reaction which results in airbag deployment can cause thermal damage and skin burning for the car passenger. The thermal burns due to airbags are of two types: burns due to direct contact with the airbag surface and burns resulting from exposure to the hot gas leaving the deflation vents of the airbag. In this research, for experimental study of the burns resulting from exposure of the skin to airbag, using infrared thermography, the extent of temperature rise of the airbag surface was detected and measured from the zero moment of its inflation. Next, using Henriques equation, the extent of thermal damage caused by airbag deployment and its resulting burn degree was calculated. The results indicated that during the inflation of airbag, the maximum temperature of its surface can be 92 °C ± 2 °C. Furthermore, if the vehicle’s safety system functions within the predicted time intervals, the risk of thermal damage is virtually zero. However, if even a slight delay occurs in detachment of the passenger’s head and face off the airbag, second- and third-degree burns could develop.

In vitro characterisation of ultrasound-induced heating effects in the mother and fetus: A clinical perspective

Ultrasound ◽  
2020 ◽  
pp. 1742271X2095319
Author(s):  
Stephanie F Smith ◽  
Piero Miloro ◽  
Richard Axell ◽  
Gail ter Haar ◽  
Christoph Lees
Keyword(s):  
Temperature Increase ◽  
Skin Surface ◽  
Maximum Temperature ◽  
Factors Affecting ◽  
Bone Interface ◽  
Heating Effects ◽  
Power Setting ◽  
Lower Temperature

Introduction The quantification of heating effects during exposure to ultrasound is usually based on laboratory experiments in water and is assessed using extrapolated parameters such as the thermal index. In our study, we have measured the temperature increase directly in a simulator of the maternal–fetal environment, the ‘ISUOG Phantom’, using clinically relevant ultrasound scanners, transducers and exposure conditions. Methods The study was carried out using an instrumented phantom designed to represent the pregnant maternal abdomen and which enabled temperature recordings at positions in tissue mimics which represented the skin surface, sub-surface, amniotic fluid and fetal bone interface. We tested four different transducers on a commercial diagnostic scanner. The effects of scan duration, presence of a circulating fluid, pre-set and power were recorded. Results The highest temperature increase was always at the transducer–skin interface, where temperature increases between 1.4°C and 9.5°C were observed; lower temperature rises, between 0.1°C and 1.0°C, were observed deeper in tissue and at the bone interface. Doppler modes generated the highest temperature increases. Most of the heating occurred in the first 3 minutes of exposure, with the presence of a circulating fluid having a limited effect. The power setting affected the maximum temperature increase proportionally, with peak temperature increasing from 4.3°C to 6.7°C when power was increased from 63% to 100%. Conclusions Although this phantom provides a crude mimic of the in vivo conditions, the overall results showed good repeatability and agreement with previously published experiments. All studies showed that the temperature rises observed fell within the recommendations of international regulatory bodies. However, it is important that the operator should be aware of factors affecting the temperature increase.

scholarly journals Characterization of New Virulence Factors Involved in the Intracellular Growth and Survival of Burkholderia pseudomallei

2015 ◽  
Vol 84 (3) ◽  
pp. 701-710 ◽  
Author(s):  
Madeleine G. Moule ◽  
Natasha Spink ◽  
Sam Willcocks ◽  
Jiali Lim ◽  
José Afonso Guerra-Assunção ◽  
...  
Keyword(s):  
Burkholderia Pseudomallei ◽  
Insertion Site ◽  
Wild Type ◽  
Content Type ◽  
Growth And Survival ◽  
New Genes ◽  
Insertion Sites

Burkholderia pseudomallei, the causative agent of melioidosis, has complex and poorly understood extracellular and intracellular lifestyles. We used transposon-directed insertion site sequencing (TraDIS) to retrospectively analyze a transposon library that had previously been screened through a BALB/c mouse model to identify genes important for growth and survivalin vivo. This allowed us to identify the insertion sites and phenotypes of negatively selected mutants that were previously overlooked due to technical constraints. All 23 unique genes identified in the original screen were confirmed by TraDIS, and an additional 105 mutants with various degrees of attenuationin vivowere identified. Five of the newly identified genes were chosen for further characterization, and clean, unmarkedbpsl2248,tex,rpiR,bpsl1728, andbpss1528deletion mutants were constructed from the wild-type strain K96243. Each of these mutants was testedin vitroandin vivoto confirm their attenuated phenotypes and investigate the nature of the attenuation. Our results confirm that we have identified new genes important toin vivovirulence with roles in different stages ofB. pseudomalleipathogenesis, including extracellular and intracellular survival. Of particular interest, deletion of the transcription accessory protein Tex was shown to be highly attenuating, and thetexmutant was capable of providing protective immunity against challenge with wild-typeB. pseudomallei, suggesting that the genes identified in our TraDIS screen have the potential to be investigated as live vaccine candidates.

Effect of Sagittal Sawing Parameters on Histopathology of Bone

2013 ◽  
Author(s):  
Gerard Chang ◽  
Steven Micucci ◽  
Eric Smith ◽  
Charles Cassidy ◽  
Tobi Quinto ◽  
...  
Keyword(s):  
Joint Replacement ◽  
Thermal Damage ◽  
Thrust Force ◽  
Histopathological Analysis ◽  
Clinical Perspective ◽  
Tissue Necrosis ◽  
Thermal Necrosis ◽  
Joint Replacement Surgery ◽  
Replacement Surgery ◽  
Cut Surface

A sagittal saw is used for resection of bone during joint replacement surgery. During sawing, tissue at the cut surface can be damaged by high temperatures, which may lead to aseptic loosening of implants. To date, there have been no studies relating sagittal sawing parameters to the level of tissue necrosis. The aim of this study was to determine the feasibility of using histopathological analysis in assessing the severity of thermal necrosis due to sawing. All sawing experiments were performed on cortical bone taken from fresh bovine femur. A two factor, two level design of experiments was performed looking at applied thrust force from 15 N to 30 N and blade oscillation speed from 12,000 cpm to 18,000 cpm. Each cut was subjected to standard histological preparation and the depth of empty lacunae was measured. Both experimental factors, force and speed, showed a statistically significant effect on the depth of thermal necrosis (p< 0.05). However, the interaction of speed and force did not prove to be statistically significant (p = 0.22). From a clinical perspective, the results indicate that choosing higher blade speeds and applying greater force can reduce the amount of thermal damage during sagittal sawing.

Automated Retroviral Insertion Site Sequence Analysis and Mapping Tool Followed by Database Analysis.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 5528-5528
Author(s):  
Stephanie Laufs ◽  
Frank A. Giordano ◽  
Agnes Hotz-Wagenblatt ◽  
Uwe Appelt ◽  
Daniel Lauterborn ◽  
...  
Keyword(s):  
Insertional Mutagenesis ◽  
Integration Site ◽  
Query Sequence ◽  
Cpg Islands ◽  
Insertion Site ◽  
High Throughput Analysis ◽  
Site Analysis ◽  
Conventional Analysis ◽  
Integration Site Analysis ◽  
Insertion Sites

Abstract Increasing use of retroviral vector-mediated gene transfer and recent reports on insertional mutagenesis in mice and humans created intense interest to characterize vector integrations on the genomic level. Techniques to determine insertion sites, mainly based on time consuming manual data processing and compilation, are thus commonly applied in gene therapy laboratories. Since a high variability in processing methods hampers further data comparison, there is an urgent need to systematically process the data arising from such analysis. The obtained sequences from the integration site analysis are judged to be authentic only if the matching part of the genomic query sequence is surrounded by the 5′LTR-sequence on the one side and the adapter-sequence on the other side. Therefore we developed an Integrationseq tool. In this task, different methods for converting the ABI sequence trace files to high quality sequences and for recognizing and deleting the LTR and adaptor parts of the isolated clones were implemented. If neither a primer nor a LTR could be found, the sequence is discarded. If the LTR is found on the complementary strand, the integration sequence is reversed. The remaining sequence between primer and LTR positions are taken as the n integration sequence and written to a sequence output file. We validated the Integrationseq tool using 259 trace files originating from integration site analysis (LM-PCR). Sequences can be trimmed by IntegrationSeq, leading to an increased yield of valid integration sequence detection, which has shown to be more sensitive (100%) than conventional analysis (94.3%) and 15 times faster than conventional analysis, while the specifities are equal (both 100%). Valid integration sequences get further processed with IntegrationMap for automatic genomic mapping. IntegrationMap runs 50 times faster than conventional methods and retrieves detailed information about whether integrations are located in or close to genes, the name of the gene, the exact localization in the transcriptional units and further parameters like the distance from the transcription start site to the integration. Further information, e.g. data about CpG-Islands, LINEs or SINEs, and their distances to the integration is also displayed. Output files generated by the task were found to be 99.8% identical with results retrieved by conventional mapping with the Ensembl alignment tool. Using both tools, IntegrationSeq and IntegrationMap, a validated, fast and standardized high-throughput analysis of insertion sites can be achieved for the first time.

Sign in / Sign up

Export Citation Format

Share Document