XXXIIème congrès annuel de la société de Biomécanique,
Lyon,France 28-29 août 2007
XXXIIth annual meeting of French biomechanical societyLyon,France 28-29 August 2007
There is still summer outside, hot wether and we would like to put out the shues more light and comfortable and easy to put on but. Is flip-flops the best idea for such situation? Now I’m not sure.
“I have seen a wide variety of injuries, pain or strain just from wearing flip-flops,” podiatrist Dr. Jeff LaMour of Family Foot Care said.
The slinky sandals offer little protection and support for your feet and wearing them could lead to future foot problems, podiatrists say.
“It’s not uncommon for a patient to come in with arch pain, heel pain or even ankle pain as a result of wearing shoes without any support,” LaMour said.
Knowing the risks, Jessica Munice said she’s not ready to retire her favorite sandals.
“Maybe in a couple years,” she said.
The shoes should be worn sparingly, LaMour said.
“If you are really active or doing a lot of walking you would be better off wearing something with more shock absorption,” he said.
Even though the warm weather may tempt you to expose your toes, doctors hope just knowing the risks involved with wearing flip-flops may give you cold feet.
One can allow them to wear flip flop type sandals or slippers only in own garden or housing complex. When kids go out on the town, they still wears sneakers or well-made sandals.
Swissmedic is the central Swiss supervisory authority for therapeutic products. It is a public service organization of the federal government with headquarters in
Its core competence includes
Medical devices Vigilance:
In order to monitor medical devices already on the market, manufacturers and distributors placing medical devices on the Swiss market are required to report all serious incidents and recalls that are carried out for safety reasons.
To get more information about Vigilance procedure in
Vical Incorporated (Nasdaq: VICL) announced today that results from a series of HIV vaccine Phase 2a clinical trials, using a plasmid DNA (pDNA) vaccine developed by the NIH Vaccine Research Center and manufactured by Vical, reinforced previously reported Phase 1 conclusions that a “DNA prime-adenoviral vector boost” vaccine regimen was safe and well-tolerated, and was effective in inducing T-cell immune responses in up to 70% of the vaccine recipients.”These recent vaccine trials contribute to the growing body of knowledge demonstrating plasmid DNA priming as a key factor in achieving significant immune responses against HIV, a particularly difficult target pathogen, bringing us one step closer to evaluating the effectiveness of a prime-boost HIV vaccine regimen in a prophylactic setting,” said Vijay B. Samant, Vical’s President and Chief Executive Officer. “The latest International AIDS Vaccine Initiative (IAVI) listing of ongoing preventive HIV vaccine clinical trials shows that more than half use pDNA either alone or in combination with other vaccine modalities. We are very pleased that DNA technology is an integral part of the effort to address this high priority global health problem.”The trials involved priming an immune response with three doses of a pDNA vaccine over a two month period, based on Vical’s proprietary DNA technology, and boosting the response with a single dose of adenoviral vector vaccine at six months. The three trials, collectively known as TRIAD, were conducted by the National Institute of Allergy and Infectious Diseases (NIAID) HIV Trials Vaccine Network (HVTN), the IAVI, and the U.S. Military HIV Research Program (USMHRP). Richard Koup, M.D., Chief of Immunology at the Dale and Betty Bumpers Vaccine Research Center (VRC), NIAID, National Institutes of Health (NIH), highlighted TRIAD summary results and conclusions in an oral presentation, “Update on safety and immunogenicity of VRC products,” at the AIDS Vaccine 2007 conference (Seattle - August 20-23).About the VaccineThe “prime-boost” strategy uses two vaccine components given at different times. Both contain synthetic versions of genes encoding three HIV proteins: gag, pol and env. The DNA component also includes a gene encoding a fourth protein, nef. The gag, pol and nef genes come from HIV subtype B, the primary virus found in Europe and North America. The env gene encodes an HIV coat protein that allows the virus to recognize and attach to human cells. The vaccine incorporates modified env genes from subtypes A and C, most common in Africa and parts of Asia, as well as subtype B. These three subtypes collectively represent about 85 percent of HIV infections worldwide.The two vaccine components differ in how the genes are packaged. The pDNA component contains only the specific gene sequences in a pDNA ring, and cannot reconstitute into an infectious virus. The adenoviral vector component uses a replication-defective adenoviral vector to shuttle the same non-infectious gene sequences into the body. The pDNA vaccine used in the trials was developed by VRC scientists and was manufactured by Vical. The adenoviral vector vaccine was developed by VRC in collaboration with GenVec Inc., of Gaithersburg, Md., which also manufactured the adenoviral vector vaccine.About VicalVical researches and develops biopharmaceutical products based on its patented DNA delivery technologies for the prevention and treatment of serious or life-threatening diseases. Potential applications of the company’s DNA delivery technology include DNA vaccines for infectious diseases or cancer, in which the expressed protein is an immunogen; cancer immunotherapeutics, in which the expressed protein is an immune system stimulant; and cardiovascular therapies, in which the expressed protein is an angiogenic growth factor. The company is developing certain infectious disease vaccines and cancer therapeutics internally. In addition, the company collaborates with major pharmaceutical companies and biotechnology companies that give it access to complementary technologies or greater resources. These strategic partnerships provide the company with mutually beneficial opportunities to expand its product pipeline and address significant unmet medical needs. Additional information on Vical is available at http://www.vical.com/.This press release contains forward-looking statements subject to risks and uncertainties that could cause actual results to differ materially from those projected, including: whether VRC will continue development of prime-boost or other HIV vaccines and initiate additional trials as planned; whether immunogenicity results will be predictive of protection; whether the HIV vaccine or any other product candidates will be shown to be safe and effective in clinical trials; the timing, nature and cost of clinical trials; whether Vical or its collaborative partners will seek or gain approval to market the HIV vaccine or any other product candidates; whether Vical or its collaborative partners will succeed in marketing any product candidates; and additional risks set forth in the company’s filings with the Securities and Exchange Commission. These forward-looking statements represent the company’s judgment as of the date of this release. The company disclaims, however, any intent or obligation to update these forward-looking statements.In order to adapt better my posts to those who frequent my blog, I would appreciate if you answer the following question:
Ménière’s Disease is a complex, progressive disorder of the inner ear characterized by the feeling of dizziness or a “spinning” sensation (rotational vertigo) associated with hearing loss, fullness or pressure in the ear, and roaring or ringing in the ear (tinnitus).
It has been discovered that the endolymphatic sac contains a substance that stimulates the kidneys to get rid of water and sodium. Although the nature of this substance and how it is regulated are still unknown, it is tempting to speculate that the endolymphatic sac is involved in the body’s system to regulate sodium concentration. If this were true, it would explain why a low-sodium diet helps some people with Ménière’s Disease.
Treatment begins after the Meniett device performs a leakage test to verify that the earpiece is properly sealed in the external ear canal . Once the leakage test is completed successfully, the device will begin sending pressure pulses that are transmitted to the middle ear through the ventilation tube.
Pressure pulses help reduce excess endolymphatic fluid and restore the balance of the inner ear’s hydrodynamic system.
A small Introduction on different vascular layers:
The walls of all blood vessels, except the very smallest, have three distinct layers, or tunics( ‘covering’) , that surround a central blood-containing space, the vessel lumen. The innermost tunic is the tunica intima which is in direct contact with the blood in the lumen. This tunic contains the endothelium. The middle tuinic, the tunica media is mostly contained of smooth muscle cells, elastin and collagen fibers. The outermost layer of a blood vessel wall, the tunica externa(adventitia) is composed of loosely woven collagen fibers that protect and reinforce the vessel and anchor it to surrounding structure.
Main post:
As for the biomechanical properties of the vascular tissue, there has been quite a large number of studies done. Some of these studies report inflation-extension types of experiments done on scaffold of adventitia removed from a whole vessel. Others, have just removed out the adventitia and focused on media. The question is :
Is it really possible for all type of vessels to take out adventitia out of the vessel mechanically?
To my knowledge, this seems quite a local and specie dependent property. It looks that in some arteries , such as human femoral arteries, you can easily separate the adventitia from the rest of the vessel. However, according my experiments, it is almost impossible to take it as a whole intact cylinder out from common carotid, femoral, abdominal arteries and Jagular,facial,femoral,abdominal veins of rabbits. As for common carotid of rats, I may say, it may be possible though I had never really done it.
let’s consider that you have done it. Since it is a kind of bulky collagen fibers, it does not seem really impermeable to liquids. Thus, inflating of this layer, even if we can get it from the artery, seems quite a hard job.
Have you ever tried working with adventitia layer separately in inflation-extension tests? I would appreciate as you inform me on the subject.
picture taken from : reference
From the point of view of the knowledge that the doctor and the patient they have about the medication that is receiving the patient distinguish the open studies and the blind studies. In the open studies as much the investigator as the patient knows the treatment that receives the patient. Usually they are opened to the studies of prolonged acceptability and tolerance, the studies made in rare or incurables diseases, the studies badly designed and the farmacocinéticas studies. Blind person means ignorance of the identity of the treatment that is received. The blindness is used to eliminate all those subjective factors, as much on the part of the investigator as of the patient, that can bring confusion at the time of interpreting the results of a treatment in study. The blind studies are classified as well in: , 1) Simple blind person, the doctor knows the treatment that receives the patient but the patient does not know it 2) Double blind person neither the investigator nor the patient know the treatment that receives the patient , 3) Triple blind person neither the patient, nor the investigator nor the patrocinante know the assigned treatment the patients In order to establish causality, that is to say, to be able to affirm that a drug produces a certain effect or is superior to another drug, it is necessary to carry out controlled, randomized and blind studies. This type of design as much provides protection against the slant in the allocation on the part of the investigator and the slant in the evaluation of results by the investigator as by the patient. According to the number of measurements that are made of the variable in study the design can be cross-sectional or longitudinal. In the cross-sectional studies the variables in study are moderate a single time, that is to say, that register diverse characteristics of the population in study in a while determined, as if it was a photography of that population. Soon it is examined if some association between the observed characteristics exists. For example, in a certain population data can be gathered on weight, height, numbers of cholesterol and habit to smoke. Through this design it is possible to be determined if there is association between the different variables, but as the temporary sequence is not known the events, cause cannot be established/effect that is causality. In general, the cross-sectional designs are used for studies of biological processes that are carried out within the laboratories, for diagnosis and stratification (normal ranks), for description of diseases and studies of dose (phase I and 11). In the longitudinal design the evolution in the time of the variables in study is evaluated. Most of the studies in which there is an external intervention and are wanted to establish causality are longitudinal. Although frequently a cross-sectional design is more expeditious, the longitudinal design offers better information generally.
As part of their infection cycle, many viruses must package their newly replicated genomes inside a protein capsid to insure its proper transport and delivery to other host cells. Bacteriophage 29 packages its 6.6mm long double-stranded DNA into a 42 nm dia. X 54 nm high capsid via a portal complex that hydrolyses ATP. This process is remarkable because entropic, electrostatic, and bending energies of the DNA must be overcome to package the DNA to near-crystalline density.
Despite the abundant literature on blood vessel mechanical properties, blood vessel constitutive models are far less common. Blood vessels are nonlinear, anisotropic and viscoelastic, heterogeneous in the unloaded state and compressible when studying macroscopic characteristic and they behave differently in different temperatures. Despite the long list of attributes, constitutive equations generally account for only a subset of these characteristics.
In general, blood vessels can be treated as pseudoelastic, randomly elastic, poroelastic or viscoelastic . Pseudoelasticity assumes that a material can be modeled using separate equations describing the loading and unloading behavior. Random elasticity, however, assumes that the strain response for a given load is rendered around a definite value that lies on a well defined curve, such that data from both the loading and unloading curves can be included simultaneously. Poroelastic formulations treat a material as a fluid-saturated porous medium and are well suited to model wall transport. Viscoelastic formulations include time-dependent responses in the constitutive equation and are useful for modeling creep, stress relaxation, and hysteresis. Useful reviews are available, concerning the biomechanics of soft biological tissues :
Vito, R.P. and S.A. Dixon, Blood vessel constitutive models-1995-2002. Annual Review Of Biomedical Engineering, 2003. 5: p. 413-439.
Humphrey, J.D., Continuum biomechanics of soft biological tissues. Proceedings: Mathematical, Physical and Engineering Sciences (Series A), 2003. 459(2029): p. 3-46.