7 research outputs found
Development Potentials For Palestine
The author discusses issues surrounding the potential economic development of Palestine. He specifically discusses the Palestinian projects of the United Nations Development Programme in Gaza
Iron Oxide Nanoparticles Stimulates Extra-Cellular Matrix Production in Cellular Spheroids
Nanotechnologies have been integrated into drug delivery, and non-invasive imaging applications, into nanostructured scaffolds for the manipulation of cells. The objective of this work was to determine how the physico-chemical properties of magnetic nanoparticles (MNPs) and their spatial distribution into cellular spheroids stimulated cells to produce an extracellular matrix (ECM). The MNP concentration (0.03 mg/mL, 0.1 mg/mL and 0.3 mg/mL), type (magnetoferritin), shape (nanorod—85 nm × 425 nm) and incorporation method were studied to determine each of their effects on the specific stimulation of four ECM proteins (collagen I, collagen IV, elastin and fibronectin) in primary rat aortic smooth muscle cell. Results demonstrated that as MNP concentration increased there was up to a 6.32-fold increase in collagen production over no MNP samples. Semi-quantitative Immunohistochemistry (IHC) results demonstrated that MNP type had the greatest influence on elastin production with a 56.28% positive area stain compared to controls and MNP shape favored elastin stimulation with a 50.19% positive area stain. Finally, there are no adverse effects of MNPs on cellular contractile ability. This study provides insight on the stimulation of ECM production in cells and tissues, which is important because it plays a critical role in regulating cellular functions
Longitudinal Stretching for Maturation of Vascular Tissues Using Magnetic Forces
Cellular spheroids were studied to determine their use as “bioinks” in the biofabrication of tissue engineered constructs. Specifically, magnetic forces were used to mediate the cyclic longitudinal stretching of tissues composed of Janus magnetic cellular spheroids (JMCSs), as part of a post-processing method for enhancing the deposition and mechanical properties of an extracellular matrix (ECM). The purpose was to accelerate the conventional tissue maturation process via novel post-processing techniques that accelerate the functional, structural, and mechanical mimicking of native tissues. The results of a forty-day study of JMCSs indicated an expression of collagen I, collagen IV, elastin, and fibronectin, which are important vascular ECM proteins. Most notably, the subsequent exposure of fused tissue sheets composed of JMCSs to magnetic forces did not hinder the production of these key proteins. Quantitative results demonstrate that cyclic longitudinal stretching of the tissue sheets mediated by these magnetic forces increased the Young’s modulus and induced collagen fiber alignment over a seven day period, when compared to statically conditioned controls. Specifically, the elastin and collagen content of these dynamically-conditioned sheets were 35- and three-fold greater, respectively, at seven days compared to the statically-conditioned controls at three days. These findings indicate the potential of using magnetic forces in tissue maturation, specifically through the cyclic longitudinal stretching of tissues
Physician and Patient Factors Associated with Ordering a Colon Evaluation After a Positive Fecal Occult Blood Test
OBJECTIVE: Successful colorectal cancer screening relies in part on physicians ordering a complete diagnostic evaluation of the colon (CDE) with colonoscopy or barium enema plus sigmoidoscopy after a positive screening fecal occult blood test (FOBT). DESIGN: We surveyed primary care physicians about colorectal cancer screening practices, beliefs, and intentions. At least 1 physician responded in 318 of 413 (77%) primary care practices that were affiliated with a managed care organization offering a mailed FOBT program for patients aged ≥50 years. Of these 318 practices, 212 (67%) had 602 FOBT+ patients from August through November 1998. We studied 184 (87%) of these 212 practices with 490 FOBT+ patients after excluding those judged ineligible for a CDE or without demographic data. Three months after notification of the FOBT+ result, physicians were asked on audit forms if they had ordered CDEs for study patients. Patient- and physician-predictors of ordering CDEs were identified using logistic regression. MEASUREMENTS AND MAIN RESULTS: A CDE was ordered for only 69.5% of 490 FOBT+ patients. After adjustment, women were less likely to have had CDE initiated than men (adjusted odds, 0.66; confidence interval, 0.44 to 0.97). Physician survey responses indicating intermediate or high intention to evaluate a FOBT+ patient with a CDE were associated with nearly 2-fold greater adjusted odds of actually initiating a CDE in this circumstance versus physicians with a low intention. CONCLUSIONS: Primary care physicians often fail to order CDE for FOBT+ patients. A CDE was less likely to be ordered for women and was influenced by physician's beliefs about CDEs