In vitro biomechanical comparison of load to failure testing of a canine unconstrained medial compartment elbow arthroplasty system and normal canine thoracic limbs

2013 ◽  
Vol 26 (05) ◽  
pp. 356-365 ◽  
Author(s):  
K. L. Wendelburg ◽  
S. Tepic ◽  
S. M. Stover ◽  
T. Garcia-Nolen ◽  
P. B. Stearns ◽  
...  
Keyword(s):  
Axial Load ◽  
Failure Modes ◽  
Ex Vivo ◽  
Medial Compartment ◽  
Elbow Arthroplasty ◽  
Total Arthroplasty ◽  
Significant Difference ◽  
Load To Failure ◽  
And Control

SummaryElbow dysplasia, primarily affecting the medial compartment, is the most common cause of lameness in the thoracic limb. Elbow arthroplasty is an option for end stage or severely affected patients. The purpose of this study was to compare ex vivo axial load to failure of an implanted novel elbow arthroplasty system to control limbs. The partial arthroplasty is a medial compartmental, unconstrained system, intended to allow conversion to total arthroplasty. We hypothesized that there would not be any significant difference between implanted and controlled limbs when loaded to failure. Six pairs of medium mixed breed canine cadaveric thoracic limbs were prepared for comparison of failure loading of control and implanted limbs. Axial compression was performed using a mechanical testing system. Failure loads were normalized to bodyweight. The mean normalized failure load (N/kg) for the implanted limbs and control limbs were 2.47 (range: 1.62-3.38) and 2.68 (range: 2.25-3.25), respectively. An implanted to control ratio of 0.93 ± 0.19 was calculated. The difference between paired control and implanted limbs in normalized failure loading was not significant (p = 0.38). There were not any differences noted in the yield load (p = 0.30), stiffness (p = 0.62), or energy (0.58). Failure modes were recorded. We concluded that the differences between implanted and control limbs in supra-physiologic axial load to failure were not significant.

scholarly journals Tissue stress from laparoscopic grasper use and bowel injury in humans: establishing intraoperative force boundaries

2021 ◽  
Vol 3 (1) ◽  
pp. e000084
Author(s):  
Amanda Farah Khan ◽  
Matthew Kenneth MacDonald ◽  
Catherine Streutker ◽  
Corwyn Rowsell ◽  
James Drake ◽  
...  
Keyword(s):  
Small Bowel ◽  
Tissue Injury ◽  
Ex Vivo ◽  
Gastrointestinal Surgery ◽  
Convenience Sample ◽  
Thickness Change ◽  
Novel Device ◽  
Significant Difference ◽  
Laparoscopic Grasper

ObjectivesWe aim to determine what threshold of compressive stress small bowel and colon tissues display evidence of significant tissue trauma during laparoscopic surgery.DesignThis study included 10 small bowel and 10 colon samples from patients undergoing routine gastrointestinal surgery. Each sample was compressed with pressures ranging from 100 kPa to 600 kPa. Two pathologists who were blinded to all study conditions, performed a histological analysis of the tissues. Experimentation: November 2018–February 2019. Analysis: March 2019–May 2020.SettingAn inner-city trauma and ambulatory hospital with a 40-bed inpatient general surgery unit with a diverse patient population.ParticipantsPatients were eligible if their surgery procured healthy tissue margins for experimentation (a convenience sample). 26 patient samples were procured; 6 samples were unusable. 10 colon and 10 small bowel samples were tested for a total of 120 experimental cases. No patients withdrew their consent.InterventionsA novel device was created to induce compressive “grasps” to simulate those of a laparoscopic grasper. Experimentation was performed ex-vivo, in-vitro. Grasp conditions of 0–600 kPa for a duration of 10 s were used.ResultsSmall bowel (10), M:F was 7:3, average age was 54.3 years. Colon (10), M:F was 1:1, average age was 65.2 years. All 20 patients experienced a significant difference (p<0.05) in serosal thickness post-compression at both 500 and 600 kPa for both tissue types. A logistic regression analysis with a sensitivity of 100% and a specificity of 84.6% on a test set of data predicts a safety threshold of 329–330 kPa.ConclusionsA threshold was discovered that corresponded to both significant serosal thickness change and a positive histological trauma score rating. This “force limit” could be used in novel sensorized laparoscopic tools to avoid intraoperative tissue injury.

scholarly journals A Tumbling Magnetic Microrobot System for Biomedical Applications

Micromachines ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 861
Author(s):  
Elizabeth E. Niedert ◽  
Chenghao Bi ◽  
Georges Adam ◽  
Elly Lambert ◽  
Luis Solorio ◽  
...  
Keyword(s):  
Ultrasound Imaging ◽  
Biomedical Applications ◽  
Imaging System ◽  
Ex Vivo ◽  
Negative Control ◽  
Circular Path ◽  
Rotational Axis ◽  
Significant Difference

A microrobot system comprising an untethered tumbling magnetic microrobot, a two-degree-of-freedom rotating permanent magnet, and an ultrasound imaging system has been developed for in vitro and in vivo biomedical applications. The microrobot tumbles end-over-end in a net forward motion due to applied magnetic torque from the rotating magnet. By turning the rotational axis of the magnet, two-dimensional directional control is possible and the microrobot was steered along various trajectories, including a circular path and P-shaped path. The microrobot is capable of moving over the unstructured terrain within a murine colon in in vitro, in situ, and in vivo conditions, as well as a porcine colon in ex vivo conditions. High-frequency ultrasound imaging allows for real-time determination of the microrobot’s position while it is optically occluded by animal tissue. When coated with a fluorescein payload, the microrobot was shown to release the majority of the payload over a 1-h time period in phosphate-buffered saline. Cytotoxicity tests demonstrated that the microrobot’s constituent materials, SU-8 and polydimethylsiloxane (PDMS), did not show a statistically significant difference in toxicity to murine fibroblasts from the negative control, even when the materials were doped with magnetic neodymium microparticles. The microrobot system’s capabilities make it promising for targeted drug delivery and other in vivo biomedical applications.

scholarly journals The effectiveness of collaborative infertility counseling (CIC) on pregnancy outcome in infertile women undergoing in vitro fertilization: A randomized controlled trial

2019 ◽  
Author(s):  
Mahboobeh Rasoulzadeh Bidgoli ◽  
robab latifnejad roudsari ◽  
ali montazeri
Keyword(s):  
In Vitro Fertilization ◽  
Pregnancy Rate ◽  
Treatment Success ◽  
Intervention Group ◽  
Control Group ◽  
Vitro Fertilization ◽  
Infertile Women ◽  
Significant Difference ◽  
And Control

Abstract Background: Infertility is an emotional tension which influences the whole aspects of relationships in infertile couples. A main objective of infertility treatments is elevation of pregnancy rate. The present study aimed to examine the effect of collaborative counseling on pregnancy rate in infertile women, undergoing in vitro fertilization in Mashhad, Iran. Methods: In this clinical trial, 60 women with primary infertility were selected from an infertility research center and were randomly allocated into intervention (n=29) and control (n=31) groups. The intervention group received individual counseling, based on the collaborative reproductive healthcare model with collaboration of a midwife, a gynecologist and a clinical psychologist in five sessions during a two-month period. The control group received routine care. Positive pregnancy test was considered as a criterion of treatment success at the end of the study. Data were analyzed using statistical tests including independent samples t-test. Results: There was no significant difference in pregnancy rate between intervention and control groups (P = 0.298). Also, there were no significant differences in follicle and embryo numbers between two groups. However, a significant difference was observed between two groups in terms of oocyte numbers where the intervention group had more oocyte (P = 0.014). Conclusion: Overall the findings indicated that the collaborative infertility counseling did not improve treatment success in infertile women undergoing in vitro fertilization

scholarly journals Emulsion of Chloramphenicol: an Overwhelming Approach for Ocular Delivery

Folia Medica ◽  
2017 ◽  
Vol 59 (1) ◽  
pp. 23-30 ◽  
Author(s):  
Kalpesh C. Ashara ◽  
Ketan V. Shah
Keyword(s):  
Ternary Phase Diagram ◽  
Ex Vivo ◽  
Sterility Testing ◽  
Ocular Irritation ◽  
Peg 400 ◽  
Significant Difference ◽  
Oil Mixtures ◽  
Student’S T ◽  
The Impact

Abstract Background: Ophthalmic formulations of chloramphenicol have poor bioavailability of chloramphenicol in the ocular cavity. Aim: The present study aimed at exploring the impact of different oil mixtures in the form of emulsion on the permeability of chloramphenicol after ocular application. Materials and methods: Selection of oil mixture and ratio of the components was made by an equilibrium solubility method. An emulsifier was chosen according to its emulsification properties. A constrained simplex centroid design was used for the assessment of the emulsion development. Emulsions were evaluated for physicochemical properties; zone of inhibition, in-vitro diffusion and ex-vivo local accumulation of chloramphenicol. Validation of the design using check-point batch and reduced polynomial equations were also developed. Optimization of the emulsion was developed by software Design® expert 6.0.8. Assessment of the osmolarity, ocular irritation, sterility testing and isotonicity of optimized batch were also made. Results: Parker Neem®, olive and peppermint oils were selected as an oil phase in the ratio 63.64:20.2:16.16. PEG-400 was selected as an emulsifier according to a pseudo-ternary phase diagram. Constrained simplex-centroid design was applied in the range of 25-39% water, 55-69% PEG-400, 5-19% optimized oil mixture, and 1% chloramphenicol. Unpaired Student’s t-test showed for in-vitro and ex-vivo studies that there was a significant difference between the optimized batch of emulsion and Chloramphenicol eye caps (a commercial product) according to both were equally safe. Conclusion: The optimized batch of an emulsion of chloramphenicol was found to be as safe as and more effective than Chloramphenicol eye caps.

scholarly journals Efficacy and Safety Curcuma zadoaria L. to Inactivate the Hydatid Cyst Protoscoleces

2020 ◽  
Vol 15 (1) ◽  
pp. 64-71 ◽  
Author(s):  
Hossein Mahmoudvand ◽  
Mahbobeh Pakravanan ◽  
Farnaz Kheirandish ◽  
Sareh Jahanbakhsh ◽  
Maryam Sepahvand ◽  
...  
Keyword(s):  
Body Weight ◽  
Essential Oil ◽  
Hydatid Cyst ◽  
Intraperitoneal Injection ◽  
Ex Vivo ◽  
Clinical Chemistry ◽  
Hematological Parameters ◽  
Efficacy And Safety ◽  
Significant Difference

Background: The present work aimed to evaluate the chemical composition of Curcuma zadoaria essential oil and to investigate its efficacy and safety against hydatid cyst protoscoleces. Methods: Collected protoscoleces from liver fertile hydatid cysts of infected sheep were exposed to different concentrations of the essential oil (75, 150, 300 μl/mL) for 5-30 min in vitro and ex vivo. Then, by using the eosin exclusion assay, the viability of protoscoleces was studied. In the next step, 24 male NMRI mice were examined to assess the toxicity of C. zadoaria essential oil by measuring the biochemical and hematological parameters. Results: Based on the obtained results, the LD50 value of intraperitoneal injection of the C. zadoaria essential oil was 1.76 mL/kg of body weight and the maximum non-fatal dose was 0.96 mL/kg of body weight. C. zadoaria essential oil had a strong proto scolicidal activity in vitro so that at the 300 and 150 μl/ml entirely eliminates the parasite after 5 and 10 minutes; whereas, weak proto scolicidal activity was observed at lower doses. Ex vivo assay, no similar effect with in vitro was observed, therefore, more time is required to show a potent proto scolicidal activity. C. zadoaria essential oil at the concentrations of 300 and 150 μl/mL after an exposure time of 7 and 12 min, killed 100% of protoscoleces within the hydatid cyst, respectively. After intraperitoneal injection of the C. zadoaria essential oil for 2 weeks, no significant difference (p > 0.05) was observed in the clinical chemistry and hematologic parameters at the doses of 0.15, 0.3, 0.6 mL/kg. Conclusion: The obtained results in vitro and ex vivo exhibited that C. zadoaria essential oil had a favorable proto scolicidal activity on hydatid cyst protoscoleces. However, more supplementary works are required to verify these findings by assessing clinical subjects.

Correction formula for carbamylated haemoglobin in diabetic uraemic patients

2001 ◽  
Vol 38 (2) ◽  
pp. 115-119 ◽  
Author(s):  
A M A Hammouda ◽  
G E Mady
Keyword(s):  
Renal Failure ◽  
Chronic Renal Failure ◽  
Free Amino ◽  
Urea Concentration ◽  
Diabetic Patients ◽  
Amino Groups ◽  
Correction Formula ◽  
Significant Difference ◽  
And Control

The measurement of carbamylated haemoglobin is a useful indicator of uraemic state during the preceding few weeks in patients with renal failure. In diabetic uraemic patients with hyperglycaemia, glycation of haemoglobin may interfere with its carbamylation, as both reactions involve the free amino groups of the protein. The aim of this study was to investigate the carbamylation of haemoglobin in the presence of hyperglycaemia. The study included 29 patients with chronic renal failure on regular haemodialysis, 14 diabetic and 15 non-diabetic patients, and 10 healthy controls. We found a significant correlation between the degree of haemoglobin carbamylation and mean blood urea concentration in both uraemic and control subjects. Carbamylation of haemoglobin was higher in both diabetic and non-diabetic chronic renal failure patients, but there were no significant differences between the groups regarding mean blood urea concentration or level of haemoglobin carbamylation. Carbamylated haemoglobin per unit of blood urea concentration was lower in the diabetic patients. Using a correction formula to account for the degree of haemoglobin glycation, there was no longer a significant difference in carbamylation per unit of blood urea concentration. In vitro incubation of red blood cells from six healthy and six diabetic non-uraemic patients in 70mmol/L urea showed a significantly lower carbamylation in the diabetic patients, but there was no significant difference when using corrected carbamylated haemoglobin values. We conclude that glycation of haemoglobin affects its carbamylation and that monitoring of uraemia in a diabetic patient necessitates the use of carbamylated haemoglobin value corrected for the degree of glycation.

Effect of starvation on gonadotrophin secretion and on in vitro release of LRH from the isolated median eminence of the male rat

1983 ◽  
Vol 103 (3) ◽  
pp. 293-301 ◽  
Author(s):  
Michael Warnhoff ◽  
Gunter Dorsch ◽  
Karl M. Pirke
Keyword(s):  
In Vitro Release ◽  
Basic Mechanism ◽  
Male Rat ◽  
Gonadotrophin Secretion ◽  
Significant Difference ◽  
Lh Release ◽  
And Control ◽  
Vitro Release

Abstract. A perfusion system was developed in which isolated median eminences (ME) were stimulated in vitro by depolarizing agents such as potassium and veratridine. Potassium concentrations between 30 and 80 mm released increasing amounts of luteinizing hormone-releasing hormone (LRH) from the MEs of starved and control rats. Veratridine at a concentration of 50 μm caused a more prolonged LRH release in both starved and control animals. LRH secretion in vitro was slightly, though not under all conditions, significantly greater in rats starved for 5 days. The testosterone (T)-LH feedback was studied by castrating the animals and substituting various doses of T through implantation of T-releasing capsules of different sizes. The concentration in plasma, which can prevent the castration-induced much smaller in starved than in control rats. The in vitro release of LRH evoked by 80 mm potassium was not different for starved and fed rats under various feedback conditions. Both groups revealed decreased in vitro release of LRH when castrated animals were not substituted with T. The effect of castration was studied from 1 to 28 days. The plasma LH values rapidly increased in starved and control animals, indicating that the hypothalamic responsestration is not delayed by starvation. The release in vitro of LRH decreased from the first to the fifth day and remained constant thereafter. No significant difference between starved and fed rats was observed. The experiments indicate that the 'releasable pool' of LRH in vitro is greater under conditions of reduced LH release in vivo. The basic mechanism of depolarization-induced exocytosis of LRH from the ME is intact in starved animals.

A NUP98-HOX Fusion Gene Containing the Homeodomain of HOXA10 Promotes Significant Expansion of Primitive Human Hematopoietic Cells in Extended Cultures.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1351-1351
Author(s):  
Suzan Imren ◽  
Guy Sauvageau ◽  
Connie J. Eaves ◽  
R. Keith Humphries
Keyword(s):  
Cultured Cells ◽  
Fusion Gene ◽  
Ex Vivo ◽  
Hematopoietic Cells ◽  
Mouse Fibroblast ◽  
Hematopoietic Stem ◽  
Proliferative Effect ◽  
Cord Blood Cells ◽  
And Control

Abstract Expanding human hematopoietic stem cells (HSCs) in vitro is a major goal in clinical hematology but remains a major challenge due to the potent differentiating activity of known cytokines. We recently demonstrated that a NUP98-HOX fusion gene containing only the homeodomain (hd) of HOXA10 (NUP98-HOXA10hd) is a powerful stimulator of murine HSC expansion in vitro - causing &gt;1000-fold net HSC increases in 10 days (Sekulovic et al, ISEH 2005). To investigate the proliferative effect of NUP98-HOXA10hd on primitive human hematopoietic cells, highly enriched CD34+ cord blood cells were prestimulated overnight and exposed to self-inactivating MNDUSNUP98-HOXA10hd pgkGFP or control pgkGFP lentiviruses for 6h. The gene transfer efficiency into CD34+ cells determined 4 days after infection was 56 ± 5% for NUP98-HOXA10hd and 66 ± 5% for the GFP control. GFP+ cells were sorted on day 5 and then maintained for another 5 days in serum-free cultures containing Flt3-ligand, Steel factor, IL-3, IL-6 and G-CSF. An aliquot of each was then plated into “primary” colony-forming cell (CFC) assay cultures. No difference was detected in either the numbers or the types of colonies generated in these primary CFC assays of the 10-day cultured cells from the NUP98-HOXA10hd and control arms. However, when these primary CFC assays were replated into secondary CFC assays, the number of colonies obtained from the NUP98-HOXA10hd-transduced cells was 5-fold higher as compared to the GFP-control transduced cells and, upon replating into tertiary CFC assays, this difference increased to over a 100-fold. To determine the effect of NUP98-HOXA10hd on more primitive hematopoietic cells, 104 day-10 GFP+ cells were co-cultured on mouse fibroblast feeders engineered to produce human SF, IL-3 and G-SCF. At the end of 6 weeks, 13-fold more cells were recovered from the cultures initiated with NUP98-HOXA10hd-transduced cells than from the control cultures (474,000 ± 190,000 vs 37,000 ± 16,000, 3 experiments). CFC outputs were also greatly enhanced (21-fold more CFC than in the controls cultures, range=20–80, 3 experiments). Moreover, the proportion of progenitors in the assays of the cultures initiated with NUP98-HOXA10hd cells that were multi-lineage (CFU-GEMM) was &gt;10-fold higher as compared to the CFCs obtained from the control cultures (8 ± 3% vs 0.7 ± 0.7%). When this experiment was repeated using limiting dilutions of initial day-10 cells, the frequency of NUP98-HOXA10hd-transduced cells able to generate CFCs another 6 weeks later was 10-fold higher as compared to the day-10 GFP control-transduced cells. These findings document an unprecedented potency of NUP98-HOXA10hd for stimulating the ex-vivo expansion of very primitive pluripotent human hematopoietic cells.

Simplifying four-strand flexor tendon repair using double-stranded suture: a comparative ex vivo study on tensile strength and bulking

2012 ◽  
Vol 37 (2) ◽  
pp. 101-108 ◽  
Author(s):  
T. H. Low ◽  
T. S. Ahmad ◽  
E. S. Ng
Keyword(s):  
Tensile Strength ◽  
Flexor Tendon ◽  
Ex Vivo ◽  
Tendon Repair ◽  
Flexor Digitorum Profundus ◽  
Flexor Tendon Repair ◽  
Significant Difference ◽  
Load To Failure ◽  
Fresh Frozen ◽  
Flexor Digitorum

We have compared a simple four-strand flexor tendon repair, the single cross-stitch locked repair using a double-stranded suture (dsSCL) against two other four-strand repairs: the Pennington modified Kessler with double-stranded suture (dsPMK); and the cruciate cross-stitch locked repair with single-stranded suture (Modified Sandow). Thirty fresh frozen cadaveric flexor digitorum profundus tendons were transected and repaired with one of the core repair techniques using identical suture material and reinforced with identical peripheral sutures. Bulking at the repair site and tendon–suture junctions was measured. The tendons were subjected to linear load-to-failure testing. Results showed no significant difference in ultimate tensile strength between the Modified Sandow (36.8 N) and dsSCL (32.6 N) whereas the dsPMK was significantly weaker (26.8 N). There were no significant differences in 2 mm gap force, stiffness or bulk between the three repairs. We concluded that the simpler dsSCL repair is comparable to the modified Sandow repair in tensile strength, stiffness and bulking.

Accumulation of calcium by normal and dystrophin-deficient mouse muscle during contractile activity in vitro

1992 ◽  
Vol 82 (4) ◽  
pp. 455-459 ◽  
Author(s):  
A. McArdle ◽  
R. H. T. Edwards ◽  
M. J. Jackson
Keyword(s):  
Creatine Kinase ◽  
Contractile Activity ◽  
Calcium Flux ◽  
Mouse Muscle ◽  
Control Muscle ◽  
Significant Difference ◽  
And Control ◽  
Muscle Calcium ◽  
Total Muscle

1. Accumulation of calcium by extensor digitorum longus muscles from dystrophin-deficient mdx and control C57BL/10 mice has been studied in vitro by measurements of total muscle calcium and by following the retention of 45Ca resulting from the incubation of muscles with the isotope for up to 2 h. 2. The rate of influx of calcium, calculated from the retention of 45Ca, was linear over 2 h in muscles at rest with no significant difference between mdx and control muscles. 3. Repetitive tetanic stimuli caused a substantial increase in 45Ca flux into both mdx and control muscles. This elevated rate of influx was maintained by control muscle, but not by mdx muscle after stimulation resulting in a significantly smaller total calcium flux into mdx muscle compared with control muscle by 1 h after stimulation. Similar changes were also seen in the total muscle calcium content of mdx and control muscles. Comparison of these results with those for loss of cytosolic creatine kinase previously reported (McArdle, A., Edwards, R.H.T. & Jackson, M.J. Clin. Sci. 1991; 80, 367-71) [1] indicate that control and dystrophin-deficient muscles release equivalent amounts of intracellular creatine kinase in response to the same accumulation of intracellular calcium. 4. These results therefore do not support the hypotheses that dystrophin deficiency in muscle leads to increased calcium influx during contractile activity, or that dystrophin-deficient muscle shows any inherent increased permeability to cytosolic proteins.

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