scholarly journals Does the Self-Centering Mechanism of Bipolar Hip Endoprosthesis Really Work in vivo?

2005 ◽  
Vol 13 (1) ◽  
pp. 46-51 ◽  
Author(s):  
H Tsumura ◽  
N Kaku ◽  
T Torisu
Keyword(s):  
The Self ◽  
Neutral Position ◽  
Hip Joints ◽  
Hip Endoprosthesis ◽  
Osteonecrosis Of Femoral Head ◽  
Anteroposterior Radiograph ◽  
Bipolar Prosthesis ◽  
Component Motion ◽  
Bipolar Endoprosthesis

Purposes. To examine radiographically the component motion in a bipolar prosthesis and to determine whether the self-centering mechanism really works in vivo. Methods. 38 patients with 41 bipolar hip endoprostheses (30 for coxarthrosis and 11 for osteonecrosis of femoral head) were included in this study. Two radiographs of each case were taken to evaluate the self-centering mechanism. The first anteroposterior radiograph of both hip joints was taken at the maximum abduction while the patient standing on the endoprosthetic leg. The second radiograph was taken after the patient returned to neutral position while standing on 2 legs. In the present study, the order in which the radiographs were taken differed from previously reported studies. The radiographs were analysed using the method similar to that of Drinker and Murray. The adductive motion from abduction to a neutral position is within the range of inner bearing oscillation. Results. The outer head alignment changed from 23 degrees to 12 degrees in the patients with osteonecrosis. However, the valgus position of the outer head (36 degrees) remained unchanged in the patients with coxarthrosis standing on 2 legs in the neutral position. Conclusion. The self-centering mechanism of the bipolar endoprosthesis functioned in the patients with osteonecrosis, but did not work in the coxarthrosis group.

scholarly journals A biomimetic platelet based on assembling peptides initiates artificial coagulation

2020 ◽  
Vol 6 (22) ◽  
pp. eaaz4107
Author(s):  
Pei-Pei Yang ◽  
Kuo Zhang ◽  
Ping-Ping He ◽  
Yu Fan ◽  
Xuejiao J. Gao ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Binding Sites ◽  
Therapeutic Strategy ◽  
Critical Role ◽  
The Self ◽  
Membrane Glycoprotein ◽  
Tumor Site ◽  
Self Assembling ◽  
Receptor Interactions

Platelets play a critical role in the regulation of coagulation, one of the essential processes in life, attracting great attention. However, mimicking platelets for in vivo artificial coagulation is still a great challenge due to the complexity of the process. Here, we design platelet-like nanoparticles (pNPs) based on self-assembled peptides that initiate coagulation and form clots in blood vessels. The pNPs first bind specifically to a membrane glycoprotein (i.e., CD105) overexpressed on angiogenetic endothelial cells in the tumor site and simultaneously transform into activated platelet-like nanofibers (apNFs) through ligand-receptor interactions. Next, the apNFs expose more binding sites and recruit and activate additional pNPs, forming artificial clots in both phantom and animal models. The pNPs are proven to be safe in mice without systemic coagulation. The self-assembling peptides mimic platelets and achieve artificial coagulation in vivo, thus providing a promising therapeutic strategy for tumors.

scholarly journals In vivo and in vitro outcomes of alumina, zirconia and their composited ceramic-on-ceramic hip joints

2013 ◽  
Vol 121 (1412) ◽  
pp. 382-387 ◽  
Author(s):  
Herman Shah Abd RAHMAN ◽  
Dipankar CHOUDHURY ◽  
Noor Azuan Abu OSMAN ◽  
Hanie Nadia SHASMIN ◽  
Wan Abu Bakar Wan ABAS
Keyword(s):  
Hip Joints ◽  
Ceramic On Ceramic

Kinematics of the Ankle/Foot Complex: Plantarflexion and Dorsiflexion

Foot & Ankle ◽  
1989 ◽  
Vol 9 (4) ◽  
pp. 194-200 ◽  
Author(s):  
Arne Lundberg ◽  
Ian Goldie ◽  
Bo Kalin ◽  
Göran Selvik
Keyword(s):  
Plantar Flexion ◽  
Three Dimensional ◽  
Substantial Contribution ◽  
Neutral Position ◽  
Transverse Axis ◽  
Talocrural Joint ◽  
Foot Kinematics ◽  
Talocalcaneal Joint ◽  
Axis Rotation

In an in vivo investigation of eight healthy volunteers, three dimensional ankle/foot kinematics were analyzed by roentgen stereophotogrammetry in 10° steps of motion from 30° of plantar flexion to 30° of dorsiflexion of the foot. The study included all of the joints between the tibia and the first metatarsal, as well as the talocalcaneal joint, and was performed under full body load. Although the talocrural joint was found to account for most of the rotation around the transverse axis occurring from 30° of plantar flexion to 30° of dorsiflexion, there was a substantial contribution from the joints of the arch. This was seen particularly in the input arc from 30° of plantar flexion to the neutral position, where the dorsiflexion motion of these joints amounted to 10% to 41% of the total transverse axis rotation.

Influence of particulate and dissociated metal-on-metal hip endoprosthesis wear on mesenchymal stromal cells in vivo and in vitro

Biomaterials ◽  
2016 ◽  
Vol 98 ◽  
pp. 31-40 ◽  
Author(s):  
Anastasia Rakow ◽  
Janosch Schoon ◽  
Anke Dienelt ◽  
Thilo John ◽  
Martin Textor ◽  
...  
Keyword(s):  
Mesenchymal Stromal Cells ◽  
Stromal Cells ◽  
Hip Endoprosthesis ◽  
Metal On Metal

scholarly journals Silencing of long noncoding RNA HOXA11-AS inhibits the Wnt signaling pathway via the upregulation of HOXA11 and thereby inhibits the proliferation, invasion, and self-renewal of hepatocellular carcinoma stem cells

2019 ◽  
Vol 51 (11) ◽  
pp. 1-20 ◽  
Author(s):  
Jun-Cheng Guo ◽  
Yi-Jun Yang ◽  
Jin-Fang Zheng ◽  
Jian-Quan Zhang ◽  
Min Guo ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Stem Cells ◽  
Stem Cell ◽  
Wnt Signaling ◽  
Signaling Pathway ◽  
Methylation Level ◽  
Wnt Signaling Pathway ◽  
The Self ◽  
Self Renewal

AbstractHepatocellular carcinoma (HCC) is a major cause of cancer-related deaths, but its molecular mechanisms are not yet well characterized. Long noncoding RNAs (lncRNAs) play crucial roles in tumorigenesis, including that of HCC. However, the role of homeobox A11 antisense (HOXA11-AS) in determining HCC stem cell characteristics remains to be explained; hence, this study aimed to investigate the effects of HOXA11-AS on HCC stem cell characteristics. Initially, the expression patterns of HOXA11-AS and HOXA11 in HCC tissues, cells, and stem cells were determined. HCC stem cells, successfully sorted from Hep3B and Huh7 cells, were transfected with short hairpin or overexpression plasmids for HOXA11-AS or HOXA11 overexpression and depletion, with an aim to study the influences of these mediators on the self-renewal, proliferation, migration, and tumorigenicity of HCC stem cells in vivo. Additionally, the potential relationship and the regulatory mechanisms that link HOXA11-AS, HOXA11, and the Wnt signaling pathway were explored through treatment with Dickkopf-1 (a Wnt signaling pathway inhibitor). HCC stem cells showed high expression of HOXA11-AS and low expression of HOXA11. Both HOXA11-AS silencing and HOXA11 overexpression suppressed the self-renewal, proliferation, migration, and tumorigenicity of HCC stem cells in vivo, as evidenced by the decreased expression of cancer stem cell surface markers (CD133 and CD44) and stemness-related transcription factors (Nanog, Sox2, and Oct4). Moreover, silencing HOXA11-AS inactivated the Wnt signaling pathway by decreasing the methylation level of the HOXA11 promoter, thereby inhibiting HCC stem cell characteristics. Collectively, this study suggested that HOXA11-AS silencing exerts an antitumor effect, suppressing HCC development via Wnt signaling pathway inactivation by decreasing the methylation level of the HOXA11 promoter.

scholarly journals Pharmacophore hybridisation and nanoscale assembly to discover self-delivering lysosomotropic new-chemical entities for cancer therapy

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhao Ma ◽  
Jin Li ◽  
Kai Lin ◽  
Mythili Ramachandran ◽  
Dalin Zhang ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Cancer Therapy ◽  
Self Assembly ◽  
The Self ◽  
Single Drug ◽  
Drug Nanoparticles ◽  
Lysosomal Dysfunction ◽  
New Chemical Entities ◽  
Autophagy Inhibition

Abstract Integration of the unique advantages of the fields of drug discovery and drug delivery is invaluable for the advancement of drug development. Here we propose a self-delivering one-component new-chemical-entity nanomedicine (ONN) strategy to improve cancer therapy through incorporation of the self-assembly principle into drug design. A lysosomotropic detergent (MSDH) and an autophagy inhibitor (Lys05) are hybridised to develop bisaminoquinoline derivatives that can intrinsically form nanoassemblies. The selected BAQ12 and BAQ13 ONNs are highly effective in inducing lysosomal disruption, lysosomal dysfunction and autophagy blockade and exhibit 30-fold higher antiproliferative activity than hydroxychloroquine used in clinical trials. These single-drug nanoparticles demonstrate excellent pharmacokinetic and toxicological profiles and dramatic antitumour efficacy in vivo. In addition, they are able to encapsulate and deliver additional drugs to tumour sites and are thus promising agents for autophagy inhibition-based combination therapy. Given their transdisciplinary advantages, these BAQ ONNs have enormous potential to improve cancer therapy.

Enhanced Oral Bioavailability and Improved Biological Activities of a Quercetin/Resveratrol Combination Using a Liquid Self-Microemulsifying Drug Delivery System

Planta Medica ◽  
2020 ◽  
Author(s):  
Patcharawalai Jaisamut ◽  
Subhaphorn Wanna ◽  
Surasak Limsuwan ◽  
Sasitorn Chusri ◽  
Kamonthip Wiwattanawongsa ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Delivery System ◽  
Delivery System ◽  
Oral Bioavailability ◽  
Biological Activities ◽  
Area Under The Curve ◽  
Aqueous Solubility ◽  
The Self

AbstractBoth quercetin and resveratrol are promising plant-derived compounds with various well-described biological activities; however, they are categorized as having low aqueous solubility and labile natural compounds. The purpose of the present study was to propose a drug delivery system to enhance the oral bioavailability of combined quercetin and resveratrol. The suitable self-microemulsifying formulation containing quercetin together with resveratrol comprised 100 mg Capryol 90, 700 mg Cremophor EL, 200 mg Labrasol, 20 mg quercetin, and 20 mg resveratrol, which gave a particle size of 16.91 ± 0.08 nm and was stable under both intermediate and accelerated storage conditions for 12 months. The percentages of release for quercetin and resveratrol in the self-microemulsifying formulation were 75.88 ± 1.44 and 86.32 ± 2.32%, respectively, at 30 min. In rats, an in vivo pharmacokinetics study revealed that the area under the curve of the self-microemulsifying formulation containing quercetin and resveratrol increased approximately ninefold for quercetin and threefold for resveratrol compared with the unformulated compounds. Moreover, the self-microemulsifying formulation containing quercetin and resveratrol slightly enhanced the in vitro antioxidant and cytotoxic effects on AGS, Caco-2, and HT-29 cells. These findings demonstrate that the self-microemulsifying formulation containing quercetin and resveratrol could successfully enhance the oral bioavailability of the combination of quercetin and resveratrol without interfering with their biological activities. These results provide valuable information for more in-depth research into the utilization of combined quercetin and resveratrol.

Tissue Plasminogen Activator Expression in Endothelial Cells Exposed to Cyclic Strain in Vitro

1992 ◽  
Vol 1 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Toshiaki Iba ◽  
Bauer E. Sumpio
Keyword(s):  
Endothelial Cells ◽  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Cyclic Strain ◽  
Neutral Position ◽  
Messenger Ribonucleic Acid ◽  
Tissue Plasminogen ◽  
Pai 1

The effects of cyclic strain on the production of tissue plasminogen activator (tPA) and type 1 plasminogen activator inhibitor (PAI-1) by cultured endothelial cells (EC) were examined. Human saphenous vein EC were seeded in selective areas of culture plates with flexible membrane bottoms (corresponding to specific strain regions) and grown to confluence. Membranes were deformed by vacuum (-20 kPa) at 60 cycles/min (0.5 s strain alternating with 0.5 s relaxation in the neutral position) for 5 days. EC grown in the periphery were subjected to 7-24% strain, while cells grown in the center experienced less than 7% strain. The results show a significant increase in immunoreactive tPA production on days 1, 3 and 5 compared to day 0 in EC subjected to more than 7% cyclic strain. There was no significant elevation of tPA in the medium of EC subjected to less than 7% strain. tPA activity could only be detected in the medium of EC subjected to more than 7% cyclic strain. PAI-1 levels in the medium were not significantly different in either group. In addition, immunocytochemical detection of intracellular tPA and messenger ribonucleic acid (mRNA) expression of tPA (assessed by the reverse transcriptase polymerase chain reaction utilizing tPA specific sense and antisense primers) was significantly increased in EC subjected to more than 7% cyclic strain. We conclude that a 60 cycles/min regimen of strain that is greater than 7% can selectively stimulate tPA production by EC in vitro and may contribute to the relative nonthrombogenicity of the endothelium in vivo.

Friction in Hip Hemiendoprostheses. Review of Literature and Own Model Using Cadaveric Acetabula

2002 ◽  
Vol 12 (2) ◽  
pp. 126-134
Author(s):  
L.P. Müller ◽  
J. Degreif ◽  
H. Hely ◽  
D. Mehler ◽  
M. Otto ◽  
...  
Keyword(s):  
Animal Experiments ◽  
Calf Serum ◽  
Hip Joints ◽  
Hip Simulator ◽  
Total Endoprosthesis ◽  
Flexion Extension ◽  
Pin On Disc ◽  
On Line ◽  
Frictional Coefficients

The science of tribology concerning hip arthroplasty has mainly dealt with total endoprosthesis, whereas measurement values of hemiendoprosthetic implants are rare. The small amount of experimental tribologic data concerning hemiendoprosthetic implants in the form of pendulum trials, animal experiments, in vivo measurements on human hip joints and pin on disc studies will be reviewed in the following work. The reported frictional coefficients in these studies were between 0.014–0.57. In order to test the friction coefficients of different femur head hemiendoprostheses (unipolar ceramic- and metal heads) against fresh cadaveric acetabula, the HEPFlEx-hip simulator (Hemi-EndoProsthesis Flexion Extension) was developed. In the simulator, the various hemiendoprosthetic heads are placed on a special cone and tested against a cadaver acetabulum cast in MCP 47 woodmetal. The plane of movement of the apparatus is uniaxial with a flexion-extension movement of ± 35 degrees. The force is produced pneumatically with amounts of up to 5 kN. Newborn calf serum serves as a lubricant. A PC collects the data from torque-, force-, and angle-sensors on-line and allows the simultaneous processing and visualization of the data. The frictional coefficients produced by the different head materials and the relevance of the play between the hemiendoprothesis head size and acetabulum can be determined. Preliminary results showed that the mean friction coefficient at 1 kN loading was μ=0.024–0.063 for ceramic against cartilage and μ=0.033–0.075 for metal against cartilage.

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