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Biomedical subjects

S Schroeder

Publications and source records attributed to S Schroeder.

97 records · Page 6Linked to original sources
PubMedDate not supplied

Early postnatal growth of low birthweight infants in the WIC program.

Patterns of early postnatal growth were analyzed among low birthweight infants enrolled in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC). Infants were divided into four groups according to their neonatal status: (1) term, normal birthweight (NBW); (2) term, low birthweight (LBW); (3) moderately preterm LBW; and (4) very preterm LBW. Comparison of mean weight and length z-scores indicated that term NBW and very preterm LBW infants were at or near the national reference averages at 8, 12, and 18 months. Term LBW and moderately preterm infants were lighter and shorter than the other two study groups at each visit. Term LBW and moderately preterm infants displayed evidence of catch-up growth during the study period. Catch-up growth was defined as a decrease in the percentage of infants below the 10th percentile for weight. The effect of neonatal body proportions on postnatal growth was investigated in term LBW infants. The infants were divided into two groups based on their ponderal index (PI) at birth (low PI and proportionate PI). Comparison of weight and length z-scores indicated that both groups of term LBW infants improved in z-scores between birth and the first visit (approximately 8 months). However, infants with evidence of asymmetric intrauterine growth restriction (low PI) continued to improve in weight and length z-scores, whereas those with symmetric growth restriction (proportionate PI) remained lighter and shorter.

Birth Weight↗
PubMedDate not supplied

Influence of vessel size, age and body mass index on the flow-mediated dilatation (FMD%) of the brachial artery.

BACKGROUND: The non-invasive determination of the endothelial dysfunction (ED) of the brachial artery is a widely used method in clinical research. It remained, however, unclear, whether the test-results are influenced by the anatomical vessel size, the patients age, body mass index (BMI) or gender. METHODS: The flow-mediated vasodilatation (FMD%) of the brachial artery was determined in 122 consecutive (88 male, 34 female) patients. FMD% was measured using high resolution ultrasound (13 Mhz) at rest, during reactive hyperaemia and after the sublingual administration of glycerolnitrate (GTN%). RESULTS: Lumen diameters at rest varied from 2.48 mm to 6.33 mm (4.46+/-0.74 mm). The extent of FMD% as well as of GTN% showed an inverse correlation to the resting lumen diameters (r=-0.33, P<0.001/r=-0.51, P<0.001). This correlation was even more distinct in females (females: FMD% r=-0.54, P<0.001; GTN% r=-0.64, P<0.001 vs. males: FMD% -0.23, P<0.001; GTN% -0.59, P<0. 001). No significant influence of age (61+/-9 years, FMD%: r=-0.04, P=0.68, GTN%: r=-0.18, P=0.05) and BMI (27.03+/-3.43 kg/m(2), FMD%: r=0.16, P=0.08, GTN%: r=0.09, P=0.3) on the test results were found. CONCLUSIONS: FMD% was found to be rather independent of age or BMI. The anatomical vessel size had an influence on the test results, which was more obvious in female patients. Our data indicate the necessity of further methodological studies, in larger, community-based populations. In particular, it needs to be clarified, whether vessel size or even gender-specific correction factors are required when using this technique in routine clinical practice.

Adult↗
PubMedDate not supplied

Imaging of lymphoid structures with indium-111-labeled lymphocytes.

The ability of indium-111 (111In)-oxine-labeled syngeneic lymphocytes to migrate normally and their suitability for imaging both normal lymphoid structures and those with metastatic disease were assessed. Sixty-two ACI rats were studied, 34 of which received injections in the left foot pad with 1 X 10(6) syngeneic H-4-II-E hepatoma cells nine to 44 days before imaging. Most animals were bearing palpable tumors when imaged. In 53 experiments, 1-6 X 10(8) 111In-oxine-labeled lymphocytes with a labeling concentration of 5-80 microCi/10(8) cells were injected intravenously. Gamma camera images were obtained 22 hours later. After the last image, the animals were killed. The lymph nodes, liver, spleen, lungs, and left femur were dissected, and the recovered radioactivity was determined in a gamma well counter. Lymph nodes could be partially or completely visualized in 70% of the animals (15 tumor-bearing and 16 normal out of 44 technically satisfactory experiments). Large metastatic nodes were seen clearly. Lymphocytes labeled with 111In-oxine exhibited a normal migration from blood to lymph nodes.

Animals↗
PubMedDate not supplied

Accuracy of density measurements within plaques located in artificial coronary arteries by X-ray multislice CT: results of a phantom study.

PURPOSE: Clinical studies indicate that coronary plaque morphology might be differentiated noninvasively using multislice CT by determining tissue density within the lesions. The aim of the present experimental study was to evaluate factors that influence density measurements within small vessels. METHOD: A coronary phantom model was developed, consisting of silicon tubes (lumen diameter 4 mm) with two plaques of known density inside, simulating soft and intermediate lesions (Plaque 1: -39 HU; Plaque 2: 72 HU). Density measurement were conducted in three different contrast medium concentrations (1:30, 1:40, 1:50) and two different slice widths (4 x 2.5 mm, 4 x 1 mm). All scans were performed on a Somatom Volume Zoom (Siemens, Forchheim, Germany). Experimental results were compared with calculated data based on computer simulation. RESULTS: The two plaques could be clearly differentiated from each other on both collimations (4 x 2.5 mm: Plaque 1, 85 +/- 61 HU vs. Plaque 2, 119 +/- 26 HU, p < 0.0001; 4 x 1 mm: Plaque 1, 50 +/- 54 HU vs. Plaque 2, 91 +/- 17 HU, p < 0.0001). Significantly lower and more accurate results were achieved with 1.0 mm collimation (p < 0.0001). Contrast medium concentration contributed significantly to the measurements (p < 0.001). The experimental findings were confirmed by computer simulation, which revealed even more accurate results when using a 0.5 mm collimation (Plaque 1, 0.5 mm: -9 HU vs. 4 x 1 mm: 14 HU, Plaque 2, 4 x 0.5 mm: 83 HU vs. 4 x 1 mm: 93 HU). CONCLUSION: Density measurements were found to be highly dependent on slice width and surrounding contrast enhancement. Our results indicate that standardization of methodology is required before the noninvasive differentiation of human plaque morphology by multislice CT can be applied in the clinical setting as a screening test for coronary soft plaques.

Analysis of Variance↗
PubMedDate not supplied

Reduction of peak pressure on the forefoot with a rigid rocker-bottom postoperative shoe.

An ideal postoperative shoe should be comfortable to wear and protect the foot during recovery from surgery or injury. Protection is assumed to be related to peak pressure and force-time integral under the foot. This study compared a commonly used postoperative shoe with a new postoperative shoe that incorporates a rigid sole with an 11 degrees rocker bottom. The new postoperative shoe significantly reduced peak pressures on the forefoot by 20%. The amount of pressure and force-time integral reduction is compared with other values found in the literature for various shoe modifications. Indications for rocker-bottom shoes are also explored.

Biomechanical Phenomena↗
PubMedDate not supplied

Effects of low to moderate lead exposure on slow cortical potentials in young children: two year follow-up study.

A follow-up study of slow cortical potentials in children with elevated blood lead (PbB) histories was conducted two years after initial evaluation. An age x PbB interaction was again observed wherein slow wave (SW) voltage varied as a linear function of PbB with the slope of the function dependent on age. The linear relationship of SW voltage and PbB was significant using either original PbB values, (14-55 micrograms/dl), follow-up values (11-39 micrograms/dl), or the mean of the two PbB values. No evidence of a threshold for this effect was observed. The similarity of results obtained at initial and follow-up assessments suggests that the observed alterations in CNS function are persistent, despite a significant decrease in mean PbB across time. The observed change in SW voltage at PbB levels previously considered to be harmless suggests the need to reconsider the currently accepted 30 micrograms/dl threshold for undue lead absorption in children.

Cerebral Cortex↗