Does the choice of bottle nipple affect the oral feeding performance of very-low-birthweight (VLBW) infants?

BACKGROUND: There is a continuous debate regarding the best bottle nipple to be used to enhance the bottle-feeding performance of a preterm infant. Aim: To verify that feeding performance can be improved by using the bottle nipple with the physical characteristics that enhance infants' sucking skills. METHODS: Ten "healthy" VLBW infants (941+/-273 g) were recruited. Feeding performance was monitored at two time periods, when taking 1-2 and 6-8 oral feedings/d. At each time and within 24 h, performance was monitored using three different bottle nipples offered in a randomized order. Rate of milk transfer (ml/min) was the primary outcome measure. The sucking skills monitored comprised stage of sucking, suction amplitude, and duration of the generated negative intraoral suction pressure. RESULTS: At both times, infants demonstrated a similar rate of milk transfer among all three nipples. However, the stage of sucking, suction amplitude, and duration of the generated suction were significantly different between nipples at 1-2, but not 6-8 oral feedings/d.CONCLUSION: We did not identify a particular bottle nipple that enhanced bottle feeding in healthy VLBW infants. Based on the notion that afferent sensory feedback may allow infants to adapt to changing conditions, we speculate that infants can modify their sucking skills in order to maintain a rate of milk transfer that is appropriate with the level of suck-swallow-breathe coordination achieved at a particular time. Therefore, it is proposed that caretakers should be more concerned over monitoring the coordination of suck-swallow-breathe than over the selection of bottle nipples.

Perfusion in rat brain at 7 T with arterial spin labeling using FAIR-TrueFISP and QUIPSS.

Measurement of perfusion in longitudinal studies allows for the assessment of tissue integrity and the detection of subtle pathologies. In this work, the feasibility of measuring brain perfusion in rats with high spatial resolution using arterial spin labeling is reported. A flow-sensitive alternating recovery sequence, coupled with a balanced gradient fast imaging with steady-state precession readout section was used to minimize ghosting and geometric distortions, while achieving high signal-to-noise ratio. The quantitative imaging of perfusion using a single subtraction method was implemented to address the effects of variable transit delays between the labeling of spins and their arrival at the imaging slice. Studies in six rats at 7 T showed good perfusion contrast with minimal geometric distortion. The measured blood flow values of 152.5+/-6.3 ml/100 g per minute in gray matter and 72.3+/-14.0 ml/100 g per minute in white matter are in good agreement with previously reported values based on autoradiography, considered to be the gold standard.

THE ISOLATION AND IDENTIFICATION OF O-ACETYLATED SIALIC ACIDS ON HUMAN CELLS (NEURAMINIC ACIDS, PAPER CHROMATOGRAPHY, HUMAN MALIGNANCY, BIOSYNTHETIC LABELING)

Unlike most carbohydrates, sialic acids have a restricted distribution in nature, being present in higher animals and in certain bacteriae. Unfortunately, most studies have not taken into account the fact that the parent sialic acid molecules, N-acetyl(or N-glycolyl)-neuraminic acid can be O-substituted at the 4, 7, 8 and 9 positions, generating many compounds and isomers. The approach and results of this research study demonstrates that proportions of non-, mono-, di-, and tri-O-acetylated sialic acids can be identified and quantitated on normal and malignant human cells. This was accomplished using a paper chromatographic technique to isolate and resolve individual species of non and O-substituted sialic acids. The chemical nature of these O-substituents, as an acetyl ester, was determined on the basis of chemical degradation, enzymatic and fast atom bombardment-mass spectrometry analysis.^ The working hypothesis of this study, that O-acetylated sialic acids are expressed in a restricted manner on normal and malignant cells, was confirmed using the above experimental approach; which identified mono-, di-, and tri-O-acetylated sialic acids on a variety of normal and malignant human cells. These O-acetylated sialic acids were expressed in restricted manner on subpopulations and subcellular fractions of PHL melanoma cells. Aberrant expression of O-acetylated sialic acids was associated with adenocarcinoma of the colon, leading to a nearly complete loss of di- and tri-O-acetylated sialic acids.^ Thus, the ability to isolate and identify biosynthetically radiolabeled O-acetylated sialic acids offers an efficient method of monitoring the expression of O-acetylated sialic acids in biochemical and cellular interactions. Furthermore, the ability to identify abnormal ratios of O-acetylated sialic acids in the human colon, represents a possible diagnostic tool to evaluate and identify patients who may be genetically or culturally predisposed to the development of adenocarcinoma of the colon. ^

Investigation of arterial spin labeling MRI for quantitative cerebral blood flow measurement

Arterial spin labeling (ASL) is a technique for noninvasively measuring cerebral perfusion using magnetic resonance imaging. Clinical applications of ASL include functional activation studies, evaluation of the effect of pharmaceuticals on perfusion, and assessment of cerebrovascular disease, stroke, and brain tumor. The use of ASL in the clinic has been limited by poor image quality when large anatomic coverage is required and the time required for data acquisition and processing. This research sought to address these difficulties by optimizing the ASL acquisition and processing schemes. To improve data acquisition, optimal acquisition parameters were determined through simulations, phantom studies and in vivo measurements. The scan time for ASL data acquisition was limited to fifteen minutes to reduce potential subject motion. A processing scheme was implemented that rapidly produced regional cerebral blood flow (rCBF) maps with minimal user input. To provide a measure of the precision of the rCBF values produced by ASL, bootstrap analysis was performed on a representative data set. The bootstrap analysis of single gray and white matter voxels yielded a coefficient of variation of 6.7% and 29% respectively, implying that the calculated rCBF value is far more precise for gray matter than white matter. Additionally, bootstrap analysis was performed to investigate the sensitivity of the rCBF data to the input parameters and provide a quantitative comparison of several existing perfusion models. This study guided the selection of the optimum perfusion quantification model for further experiments. The optimized ASL acquisition and processing schemes were evaluated with two ASL acquisitions on each of five normal subjects. The gray-to-white matter rCBF ratios for nine of the ten acquisitions were within ±10% of 2.6 and none were statistically different from 2.6, the typical ratio produced by a variety of quantitative perfusion techniques. Overall, this work produced an ASL data acquisition and processing technique for quantitative perfusion and functional activation studies, while revealing the limitations of the technique through bootstrap analysis. ^

Menu labeling and food choice: A systematic review of the literature concerning the effects of menu labeling on consumer food choices

Objective: To review published literature on the impact of restaurant menu labeling on consumer food choices.^ Method: To examine all relevant studies published on the topic from 2002 to 2012.^ Results: Sixteen studies were identified as relevant and suitable for review. These studies comprised of one systematic review, one health impact assessment, and fourteen research studies conducted at restaurants, cafeterias, and laboratories. Three of ten studies conducted at restaurants and cafeterias and two of four studies conducted at laboratories found positive effects of menu labeling on consumer food choices. Conversely, the systematic review identified for this review found that five out of six studies resulted in weakly positive effects. The health impact assessment estimated positive effects; however, the results of this assessment must be cautiously interpreted since the authors used simulated data.^ Conclusion: Overall, there is insufficient evidence to provide support for the majority of the types of menu labels identified in this review on consumer food choice.^