Blood Flow Patterns

The most recent SPECT scan (single photon computed tomography of the brain) studies, by a Harvard School of Public Health physician and researcher, have shown that people with MCS have blood flow patterns in the brain that are different from those of healthy controls and from people with Chronic Fatigue Syndrome.4... 

Naruo, T., Nakabeppu, Y., Sagiyama, K., Munemoto, T, Homan, N., Deguchi, D., Nakajo, M., and Nosoe, S. (2000) Characteristics regional cerebral blood flow patterns in anorexia nervosa patients with binge/purge behavior. Am J Psychiatry 157 1520-1522. 

In general, the basic architecture of the integument is similar in all mammals. However, differences exist in the thickness of the epidermis and dermis, the number of cell layers, and the blood flow patterns between species. Additionally, differences exist within the same species at different body sites. Skin is thickest over the dorsal and lateral surfaces and thinnest on the ventral and medial surfaces of the body. The stratum corneum is thickest in glabrous skin regions such as the palmar and... 

Highly qjproximate and variable, depending on blood flow patterns. 

Regional cerebral blood flow was examined using Doppler ultrasound in 15 workers exposed to 3.2-28.9 ppm carbon disulfide for a mean of 20 years (Aaserud et al. 1992). Studies were performed 4 years after exposure ended. Asymmetrical blood flow patterns were observed in 8/14 workers, all of whom had encephalopathies consistent with carbon disulfide exposure. However, when the results were corrected to adjust for a possible influence of pC02, the values did not differ between the exposed workers and referents. No clear conclusions about this study can be made because of the small number of exposed workers, lack of a current exposure group, possible selection bias, and age variation between cohort and referents. 

Subcutaneous and intramuscular administration Subcutaneous and intramuscular administration can be used to deliver protein-based drugs. The absorption of drug is faster than with the oral route. The rate of absorption is determined by the blood flow pattern and diffusion of drug... 

One of the major goals of research in nuclear medicine is a drug that can be used to demonstrate the brain blood flow pattern. To do this job, a drug should demonstrate four properties. First, it must carry a radioactive isotope that is a positron emitter (best, a fluorine or an iodine atom, for use with the positron camera) that can be put onto the molecule quickly, synthetically, and which will stay on the molecule, metabolically. Second, as to brain entry, the... 

Kim, W.Y., Walker, P.G., Pederson, E.M., Poulsen, J.K., Houhnd, K.C., and Oyre, S. 1995. Left ventricular blood flow patterns in normal subjects a quantitative analysis of three-dimensional magnetic resonance velocity mapping. 4 422-438. 

CiciNELLi et al. [5] described an interesting pattern of collateral flow between the uterine and ovarian arterial supply to the uterus. In doing measurements of blood flow in premenopausal women, this group found there is more blood flow to the uterus from the ovarian artery during the follicular phase, whereas in the luteal phase most of the uterus is supplied from the uterine artery. Whether this change in blood flow patterns is changed in patients with fibroids is not clear. No studies of the effect of the phase of the menstrual cycle on the effectiveness of uterine artery embolization have been performed at this point. 

Nanodrug delivery for tumor treatment involves the introduction of nanodrug-loaded multifunctional nanoparticles into cancer patients to eliminate/reduce tumors while minimizing systemic toxicity. Currently, this is being attempted through various techniques which take advantage of local blood flow pattern and unique characteristics of cancer cells and the... 

Maitland et al. followed on this work with laser-activated foams for embolic aneurysm treatments [57]. In this study, the Tg of the foam was lowered to 45 °C and tested in an in vitro setup using 21 °C water, which is a 15°C shift in the Metcalfe conditions. Through proper laser power and absorption tuning, the foam devices were fully deployed under arterial flow conditions. In a parallel study, simulations were used to evaluate the performance of the device during deployment and after implantation [56]. Changes in blood flow patterns into the aneurysm, increases in hemodynamic stresses, and potential of thermal damage due to laser heating were all assessed. 

At the end of healing, fibrosis or fibrous encapsulation is the ideal response for an embolic device. The process begins with injury to the tissue and implantation of the material. Thrombi, or blood clots, begin to form immediately based on the processes previously described, over the course of minutes to hours. This is enhanced by changes in blood flow patterns, permeability of blood vessels, and composition... 

The original clamshell device was first introduced in 1989. It consisted of a double umbrella composed of four stainless steel arms covered with a polyester (Dacron ) meshwork. Each arm had a single springed hinge (see Fig. IS.S). - At the time of its introduction, double-umbrella devices were attractive because they offered the potential for minimal blood-flow pattern distortion due to their low profile. Additionally, since they possessed low alloy content, their corrosive potential was minimal. This device was deployed using an IIF sheath, which was smaller than the sheaths used by other devices at the time, but larger than those employed by the current Amplatzer Septal Occluder. ... 

The blood flow patterns within the fiber interstitial space lead to a complex convection-diffusion process that determines the mass transfer coefficient in the blood phase. Given the complexity of the mass transfer processes in blood, convective mass transfer correlations are often used for design purposes or to analyze experimental data. A convective mass transfer correlation takes the general form ... 

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