Proving the effectiveness of nurse practitioners.
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Humans↗
Biomedical subjects
Mark Smith
Publications and source records attributed to Mark Smith.
Response to Karen.
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Antipsychotic Agents↗
Idiopathic infantile arterial calcification: sonographic findings.
Idiopathic infantile arterial calcification (IIAC) is a rare disease that is characterized by calcification in the media and fibroproliferative changes in the intima of larger arteries, sometimes resulting in reduced vascular elasticity and blood flow. Although the molecular-genetic basis of the disease is unknown, IIAC is presumed to be acquired by an autosomal recessive mode of inheritance and is associated with a reduction in the levels of enzymes responsible for inorganic phosphate balance, resulting in abnormal deposition of calcium into the vessels. We report the case of a female neonate in whom widespread IIAC was initially diagnosed on postnatal sonographic examination. At birth, the infant experienced cardiac failure and hypertension, and arterial pulsation was absent. Routine prenatal sonographic examinations had not revealed any abnormalities, but postnatal gray-scale and color Doppler echocardiographic and sonographic examinations revealed findings consistent with severe IIAC. The cardiac function improved with treatment, but the neonate died of progressive hepatic failure due to reduced flow in calcified and narrowed hepatic arteries. The common carotid arteries were also grossly affected, resulting in cerebral atrophy at the time of birth. Postnatal gray-scale and color Doppler echocardiographic and sonographic examinations allowed noninvasive diagnosis, assessment of severity, and monitoring of progression.
Arterial Occlusive Diseases↗
Cryopreservation and in vitro expansion of chondroprogenitor cells isolated from the superficial zone of articular cartilage.
Understanding the proliferation mechanisms of chondroprogenitor cells and their influence on cell differentiation is crucial in order to develop large-scale expansion processes for tissue engineering applications. Proliferation control mechanisms were mainly attributed to substrate limitation and cell-cell contact inhibition. The limiting substrates were found to be components of the FCS, with an optimal proliferation rate achieved in the presence of 40% FCS. In addition, the medium supply rate was found to be essential in reducing substrate limitation. In terms of FCS, 10 microL FCS cm(-2) h(-1) was the threshold feed rate required to prevent substrate limitation. Above this rate, maximum cell densities of 5.3 x 10(5) cells/cm2 were achieved, representing a 53-fold expansion. To reduce the need for high supply rates, the effect of specific growth factors was also investigated. Cell densities of 3.3 x 10(5) cells/cm2 were achieved in batch cultures using 40% FCS and 1 ng/mL TGF-beta1. Chondroprogenitor cells were expanded in this medium up to three passages without compromising their ability to differentiate and produce cartilage-like matrix in pellet cultures. In addition to substrate limitation, cell-cell contact, even at very sparse subconfluent densities, appeared capable of exerting some degree of growth inhibition. The cells exhibited deceleratory growth kinetics, characterized by a decrease of specific growth rates over time.
Animals↗
False belief reasoning and the acquisition of relative clause sentences.
Perner (1991) has claimed that the linguistic structures and reasoning tasks mastered by 4-year-olds share a requirement to handle metarepresentation. In contrast, de Villiers (2000) has argued that they share a requirement to handle misrepresentation. In the current study, a correlation is observed between success on false belief tasks and the acquisition of relative clause sentences. This correlation is not predicted by de Villiers's account because such sentences do not require the handling of misrepresentation, but it is consistent with Perner's account because such sentences do require the handling of metarepresentation. It is proposed that only an account that integrates the accounts of both de Villiers and Perner can explain extant data on language and cognition in 4-year-olds.
Age Factors↗
Comparison of conventional spin-echo and fast spin-echo magnetic resonance imaging in the canine brain.
T2-weighted fast spin echo and conventional spin echo are two magnetic resonance (MR) pulse sequences used to image the brain. Given the same scan parameters the resolution of fast spin-echo images will be inferior to that of conventional spin-echo images. However, fast spin-echo images can be acquired in a shorter time allowing scan parameters to be optimized for increased resolution without increasing the time to an unacceptable level. MR imaging of the brain of 54 dogs, suspected of having parenchymal brain abnormalities was performed using a 1.5 T scanner. Acquisition time ranged from 4 min 24 s to 7 min 16 s (average = 5 min 15 s) for fast spin-echo scans and from 6 min 32 s to 11 min 26s (average = 7 min 55s) for conventional spin-echo scans. All reviewers consistently rated the resolution of fast spin-echo images higher than the conventional spin-echo images (P = 0.000). The potential disadvantages of fast spin-echo acquisitions (motion artifacts, blurring, and increased hyperintensity of fat) did not affect the resolution of the images. Fast spin echo offers increased resolution in a comparable time to conventional spin echo by increased number of excitations and finer matrix size, thus improving the signal-to-noise ratio and spatial resolution, respectively.
Animals↗
Will the surgical world become flat?
We obtained price and quality information for nonurgent coronary artery bypass graft (CABG) surgery from a sample of internationally patronized hospitals in low-wage countries. We found rising quality standards, availability of U.S.-trained physicians, and prices far below insurer-negotiated U.S. prices. The price differentials easily accommodated the incentive specified as a condition for surgery abroad by about 30 percent of surveyed households with a sick member. These findings foreshadow growth in offshoring of expensive nonemergency surgeries among increasingly cost-sensitive U.S. consumers and purchasers.
Accreditation↗
Challenges in improving care for high-risk seniors in Medicare.
Despite strong interest in improving care for high-risk elders, demonstration projects typically show negative results. This paper examines one large foundation-sponsored initiative to gain insight on why success often is so elusive. The findings indicate that specific flaws in concept, design, and implementation each make it more challenging for demonstrations to achieve their intended goals, especially those involving cost and utilization reductions. We speculate that part of the reason for this is that organizational and political processes lead to fundamentally conservative demonstrations that assume that small amounts of resources directed at incremental change can be effective in generating substantial change in organizations and can do so rapidly.
Aged↗