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At least 19 recordsLinked to original sources

PubMed1985

Sample attrition and multivariate analysis in the Retirement History Study.

The attrition of respondents in panel studies of older people can create bias in data analysis. Changes in the examination of attrition are suggested. Bivariate and multivariate tests comparing those eligible to respond and those actually continuing in the panel are reported for five waves of data from the Retirement History Study. The results indicate that variable relationships in the data examined are relatively free of the bias that can be created by respondent attrition. Thus, attrition from samples of older respondents probably is less of a factor than suggested by previous studies reporting on frequency distributions.

Aging↗

PubMed1989

Nonlinear dopamine pharmacokinetics in pediatric patients.

Dopamine steady-state concentrations were determined in 15 pediatric patients from 3 days to eight years of age receiving continuous infusions of dopamine. The first-order kinetic model does not accurately describe the kinetics of dopamine in these patients based on the finding that clearance varied as a function of concentration. A saturable protein binding model is described and provides a more accurate description of the behavior of the data. Using multivariate analysis, changes in dopamine kinetics were found as a function of weight. Furthermore, the co-administration of dobutamine altered the kinetics of dopamine. These data support the use of free dopamine concentrations rather than total concentration for studies of dopamine pharmacokinetics. Evaluation of total clearance of dopamine is of limited value, and changes in protein binding and intrinsic clearance must be considered in future studies of this drug.

Child, Preschool↗

PubMed1993

Trends in body composition for infants and children in the U.S.

Nationally representative health examination surveys have collected anthropometric measurements on children and adolescents in the U.S. These data may serve as very crude indicators of total fat or fat-free body mass, but do not yield information on body composition per se. Attempts to accurately describe trends in obesity for children and adolescents have been complicated by a number of limitations associated with body measurements taken over time in sequential surveys. Inferences from limited anthropometric measures should be made cautiously. Factors to consider include the selection of cutpoints for trend analysis, changes that may be within range of technical measurement error, and use of data at extreme percentiles. Ostensible trends may be genuine, but they may also be influenced by methodological differences across surveys. Comparative data are presented for selected body measures from 1963 to 1980 for U.S. children and adolescents sampled in national health examination surveys, and apparent differences are discussed.

Adult↗

PubMed1979

Basic cost analysis can improve in-service education.

When the director of a hospital's in-service education department analyzed basic cost data regarding his staff, he discovered an unnecessarily wide range of costs per student hour. The analysis changed his conception of the ideal educator, and he subsequently reorganized his department. The process he used is detailed herein.

Budgets↗

PubMed1993

Decreased type VI collagen gene expression in cultured Werner's syndrome fibroblasts.

Gene expression of collagens VI, I, and III in Werner's syndrome was studied by measuring messenger RNA (mRNA) and protein production levels in four fibroblast strains from patients with Werner's syndrome and comparing them with age-matched healthy subjects. Levels of type VI collagen mRNA were decreased in all Werner's syndrome fibroblast strains and the decreases were in parallel in all three chains (alpha 1, alpha 2, and alpha 3) of type VI collagen. A coordinate increase of the alpha 1(I) and alpha 1(III) collagen mRNA levels was observed in three of the four Werner's syndrome fibroblast strains. However, no qualitative abnormality of these mRNA transcripts in Werner's syndrome fibroblasts were found by Northern blot analysis. Changes in type VI and type I collagen mRNA correlated well with production levels of corresponding proteins, as determined by immunologic assays. These data suggest that there are changes in expression of multiple connective tissue constituents in Werner's syndrome fibroblasts.

Adult↗

PubMed1991

Re-investigation of ontogenesis of epidermal growth factor receptor mRNA in the liver of rats: quantitative evaluation of northern blot analysis.

Changes in the expression rate of epidermal growth factor receptor (EGFR) mRNA with age in the liver of rats were examined to assess the contribution of EGF to the proliferation of hepatocytes in younger animals. Northern blot analyses with a 32P-labeled probe derived from the extracellular domain of EGFR cDNA were evaluated quantitatively by normalizing the densitometric scanning data with the relative amounts of poly(A)+ RNA in the samples. The expression of EGFR mRNA was low during the early period and increased towards the adult level after 21 days of birth. In contrast, the rate of beta-actin mRNA expression was significantly higher immediately after birth and showed a tendency to decrease with time.

Actins↗

PubMed1997

Three-dimensional endosonography for staging of rectal cancer.

OBJECTIVE: This prospective study was conducted to investigate the value of three-dimensional (3D) endosonography for staging of rectal cancer. SUMMARY BACKGROUND DATA: Transrectal ultrasound is the most sensitive technique for peroperative staging and follow-up of rectal cancer. Major limitations of this technique include the complexity of image interpretation and the inability to examine stenotic tumors or to identify recurrent rectal cancer. METHODS: Three-dimensional endosonography was performed in 100 patients with rectal tumors. Transrectal volume scans were obtained using a 3D multiplane transducer (7.5/10.0 MHz). Stenotic tumors were examined with a 3D frontfire transducer (5.0/7.5 MHz). The volume scans were processed and analyzed on a Combison 530 workstation (Kretztechnik, Zipf, Austria). RESULTS: The 3D endosonography and conventional endosonography were performed in 49 patients with nonstenotic rectal cancer. Display of volume data in three perpendicular planes or as 3D view facilitated the interpretation of ultrasound images and enhanced the diagnostic information of the data. The accuracy of 3D endosonography in the assessment of infiltration depth was 88% compared to 82% with the conventional technique. In the determination of lymph node involvement, 3D and two-dimensional endosonography provided accuracy rates of 79% and 74%, respectively. The 3D scanning allowed the visualization of obstructing tumors using reconstructed planes in front of the transducer. Correct assessment of the infiltration depth was possible in 15 of 21 patients with obstructing tumors (accuracy, 76%). Three-dimensional endosonography displayed suspicious pararectal lesions in 30 patients. Transrectal ultrasound-guided biopsy was extremely precise (accuracy, 98%) and showed malignancy in 10 of 30 patients. Histologic analysis changed the endosonographic diagnosis in 8 (27%) of the patients. CONCLUSIONS: The 3D endosonography permits examination of rectal cancer using previously unattainable planes and 3D views. The 3D imaging and ultrasound-guided biopsy seem capable to improve staging of rectal cancer and should be evaluated in further studies.

Endosonography↗

PubMed1998

Prediction of indications for valve replacement among asymptomatic or minimally symptomatic patients with chronic aortic regurgitation and normal left ventricular performance.

BACKGROUND: Optimal criteria for valve replacement are unclear in asymptomatic/minimally symptomatic patients with aortic regurgitation (AR) and normal left ventricular (LV) performance at rest. Moreover, previous studies have not assessed the prognostic capacity of load-adjusted LV performance ("contractility") variables, which may be fundamentally related to clinical state. Therefore, 18 years ago, we set out to test prospectively the hypothesis that objective noninvasive measures of LV size and performance and, specifically, of load-adjusted variables, assessed at rest and during exercise (ex), could predict the development of currently accepted indications for operation for AR. METHODS AND RESULTS: Clinical variables and measures of LV size, performance, and end-systolic wall stress (ESS) were assessed annually in 104 patients by radionuclide cineangiography at rest and maximal ex and by echocardiography at rest; ESS was derived during ex. During an average 7.3-year follow-up among patients who had not been operated on, 39 of 104 patients either died suddenly (n = 4) or developed operable symptoms only (n = 22) or subnormal LV performance with or without symptoms (n = 13) (progression rate=6.2%/y). By multivariate Cox model analysis, change (delta) in LV ejection fraction (EF) from rest to ex, normalized for deltaESS from rest to ex (deltaLVEF-deltaESS index), was the strongest predictor of progression to any end point or to sudden cardiac death alone. Unadjusted deltaLVEF was almost as efficient. Symptom status modified prediction on the basis of the deltaLVEF-deltaESS index. The population tercile at highest risk by deltaLVEF-deltaESS progressed to end points at a rate of 13.3%/y, and the lowest-risk tercile progressed at 1.8%/y. CONCLUSIONS: Currently accepted symptom and LV performance indications for valve replacement, as well as sudden cardiac death, can be predicted in asymptomatic/minimally symptomatic patients with AR by load-adjusted deltaLVEF-deltaESS index, which includes data obtained during exercise.

Aortic Valve Insufficiency↗

PubMed1993

Developmental profile of the gene expression of a Bombyx homolog of mammalian sorbitol dehydrogenase during embryogenesis in non-diapause eggs.

1. By using semi-quantitative PCR analysis, changes in the amount of the transcript for a Bombyx homolog of mammalian sorbitol dehydrogenase (BmSDH) were examined during embryogenesis in non-diapause eggs. 2. Occurrence of the transcript for BmSDH correlated with the two developmental phases, the growth of embryo and the formation of larval tissues. 3. In the first phase, an increase in the amount of the transcript for BmSDH resulted from embryonic cells rather than yolk cells. 4. In the second phase, the transcript was suggested to be abundant in fat-body cells of pharate larva, because it was abundant in fat-bodies of 5th instar larvae. 5. The difference in the expression of BmSDH gene between diapause and non-diapause eggs is discussed.

Animals↗

PubMed1995

Modulation of ras transformation affecting chromatin supraorganization as assessed by image analysis.

Changes in chromatin supraorganization defined in terms of patterns of chromatin texture were studied by video image analysis in Feulgen-stained revertants of LTR-ras-transformed NIH 3T3 cells and in cell lines obtained by transfection of these revertants with sense and antisense constructs of the lysyl oxidase gene (also named Lox or "ras recision gene"). The objective was to determine whether changes in expression of the Lox gene, which have been assumed to modulate cell transformation by ras, could also affect the chromatin supraorganization changes known to be elicited in NIH 3T3 cells by ras transformation. The image analysis results revealed that, although a nuclear phenotype visually similar to the most frequent one (III) in ras-transformed NIH 3T3 cells also appeared in the revertant, it contained a remarkably less tight chromatin packing state. This situation was also found in the revertant transfected with the sense construct of the Lox gene, but in the revertant transfected with the Lox antisense constructs the chromatin texture of the III phenotype was equal to or close to that of the ras-transformed cells. With regard to the nuclear phenotype characterized by abundant loosely packed chromatin and less represented in the transformed cell lines (I'), changes in the various cell lines, although detectable, were not as drastic as those reported for the III phenotype. The enhancement in chromatin condensation of the type III nuclei, which affects euchromatin, is probably associated with a limited transcription of the genome. Although the image analysis results are mostly in agreement with previously published data on the molecular biology and tumorigenicity of the same cell lines, it appears that the phenomenon of chromatin condensation once established in NIH 3T3 cells by LTR-ras transformation could not be totally reverted by simply affecting Lox expression.

3T3 Cells↗

PubMed1996

Effect of the membrane biocompatibility on nutritional parameters in chronic hemodialysis patients.

Malnutrition is highly prevalent in chronic hemodialysis patients and is an important determinant of their morbidity and mortality. Several recent studies have suggested that the inflammatory response associated with the biocompatibility of the dialysis membranes is a potential contributing factor. In a prospective study of 159 new hemodialysis patients from two centers randomized to either a low-flux biocompatible (BCM) membrane or a low-flux bioincompatible (BICM) membrane, we measured the long-term effects of biocompatibility on several nutritional parameters, including estimated dry weight, serum albumin, insulin-like growth factor-1 (IGF-1), and prealbumin over 18 months. Our results show that the BCM group had a mean (+/- SD) increase in their dry weight of 2.96 +/- 6.88 kg at month 12 and 4.36 +/- 8.57 kg at month 18 (P < 0.05 vs. baseline for both), whereas no change in mean weight was observed in BICM group. Following initiation of hemodialysis, a significant increase was observed in serum albumin levels in both groups of patients. However, the biocompatible group had an earlier and more marked increase in serum albumin levels compared to the BICM group. The average increase in serum albumin compared to baseline was consistently greater than 0.25 g/dl after seven months in the BCM group, but did not reach this level until 12 months after initiation of dialysis in the BICM group. The difference between the groups was statistically significant at months 7, 8, and 10 (P < 0.05, higher in the BCM group). Furthermore, the overall difference in serum albumin concentration between the two groups was larger in the center where the dose of dialysis was equivalent (P < 0.001). A consistently higher value was also observed in IGF-1 levels for BCM patients compared to BICM group (P = NS). In a further analysis, changes in IGF-1 levels, but not prealbumin, predicted the subsequent changes in serum albumin. We conclude that biocompatible hemodialysis membranes favorably impact on the nutritional status of chronic hemodialysis patients, independently of the flux characteristics of the membranes, and that IGF-1 may be an early marker of nutritional status.

Adult↗

PubMed1996

A 15-year longitudinal study of Halstead-Reitan neuropsychological test performance.

Using a two-stage growth curve analysis, change over time in performance on tests in the Halstead-Reitan Battery and Average Impairment Rating (AIR) was assessed for 53 individuals who varied in age and health status. In the first stage of the analysis, estimated slope and intercept values were calculated for each individual by regressing longitudinal data points on time. In the second stage, estimated slope and intercept values obtained in the first-stage analysis were regressed on age at entry into the study with statistical control for health status, education, occupation, and gender. Control for health status had an insignificant influence on magnitude of associations between age and test performance. Age-at-entry into the study was associated with statistically significant increasing change over time (poorer performance) for tests placing relatively heavy demands on speed of psychomotor performance and for AIR.

Adult↗

PubMed1997

Aortic valve replacement for aortic stenosis with severe left ventricular dysfunction. Prognostic indicators.

BACKGROUND: Aortic valve replacement for aortic stenosis (AS) carries an increased risk in the presence of left ventricular (LV) systolic dysfunction. Few data are available on the outcome of such patients. METHODS AND RESULTS: Between 1985 and 1992, 154 consecutive patients (107 men and 47 women) with LV systolic dysfunction (ejection fraction [EF] < or = 35%) underwent aortic valve replacement for AS. The mean preoperative characteristics included EF, 27 +/- 6%; aortic valve mean gradient, 44 +/- 18 mm Hg; aortic valve area, 0.6 +/- 0.2 cm2; and cardiac output, 4.1 +/- 1.5 L/min. Simultaneous coronary artery bypass graft surgery was performed in 78 patients (51%). Perioperative (30-day) mortality was 9% (14 of 154 patients). Fifty patients died during follow-up. Coronary artery disease (P = .002) and a reduced preoperative cardiac output (P = .03) were significantly related to reduced overall survival rate by multivariate analysis. Postoperative improvement occurred in most patients; 88% were New York Heart Association class III or IV before surgery versus 7% after surgery. Postoperative EF was assessed in 76% of survivors; 76% of these demonstrated improvement. By multivariate analysis, change in EF was inversely related to coronary disease (P = .002) and preoperative aortic valve area (P = .03). CONCLUSIONS: Despite LV dysfunction, the risk of aortic valve replacement for AS was acceptable and related to coronary artery disease and mean aortic gradient, and long-term survival was related to coronary disease and cardiac output. Improvement in symptoms and EF occurred in most patients.

Adult↗

PubMed1986

Hemodynamic effects of environmental hyperthermia in stage 18, 21, and 24 chick embryos.

Environmental hyperthermia is a hazard to the poikilothermic chick embryo. We studied effects of hyperthermia on mean vitelline arterial blood pressure and mean dorsal aortic blood flow in stage 18, 21, and 24 chick embryos. The pressure was measured with a servo-null micropressure system, and the blood flow was measured with a 20 MHz pulsed Doppler flowmeter. Temperature was monitored with a needle thermoprobe positioned adjacent to the embryo. Data were obtained at 37 degrees C, after warming to 40 degrees C, and then after cooling to 37 degrees C. At stage 21, the pressure increased from 0.96 +/- 0.05 (+/- SE) to 1.04 +/- 0.06 mm Hg on warming and returned from 1.05 +/- 0.04 to 0.87 +/- 0.04 mm Hg on cooling. Pressure measurements during warming and cooling were performed in two separate groups of embryos because of technical problems. The blood flow, studied using different groups of the embryo from the pressure study, also increased from 0.65 +/- 0.06 to 0.75 +/- 0.06 mm3/s on warming and returned to 0.56 +/- 0.05 mm3/s. The heart rate increased from 173 +/- 2 to 211 +/- 3 at 40 degrees C and returned to 170 +/- 3 at 37 degrees C. Stroke volume (flow/heart rate) did not change during the temperature variation. Vascular resistance, the quotient of pressure to blood flow obtained by a ratio analysis, changed from 1.53 +/- 0.33 (median +/- 95% confidence interval) to 1.42 +/- 0.29 mm Hg/mm3/s on warming and changed to 1.60 +/- 0.32 mm Hg/mm3/s on cooling. Similar results were obtained at stages 18 and 24.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1998

Ambulatory device for surface EMG recordings.

The principles of electromyographic (EMG) analysis can be divided into the following groups: signal or motor unit shape analysis, amplitude analysis, multi-channel or successive time difference analysis, signal frequency composition analysis, change of frequency time based analysis based on simultaneous amplitude or frequency based analysis or concentric and excentric work based shape and amplitude ratio analysis. The aim of this paper is to present an ambulatory portable device for surface EMG analysing both for integrated EMG and for spectral analysis. The reliability of surface EMG recordings have established. The recent new technology gets a possibility to measure by reliable way surface EMG on-line during exercise, rehabilitation or occupational conditions. Portable EMG measurement unit and analysing program seems to be suitable for documentation of the response of rehabilitation programs, effects of physiotherapy, analysing the muscle balance and activity of sportsman and for documentation of occupational health problems. Automatic interpretation and wide data base for patient data makes the system useful in daily practice.

Ambulatory Care↗

PubMed1992

Trend analysis of solar ultraviolet exposure of the Austrian population caused by holiday patterns since 1969.

Over the last few decades, a steady increase in the incidence of skin cancer has been observed. Solar ultraviolet (UV) exposure is undoubtedly one of the primary causes, and of these, holiday patterns are an intrinsic component. To assess solar UV exposure for this trend analysis, changes in holiday patterns were investigated. For Austrians, a preponderance of holidays are spent at the Mediterranean Sea. These holidays represent not only a potentially high UV exposure because of location but also because sun-intensive activities are preferred. The analysis shows an increase in solar UV exposure from all holidays of 1.6% per year. About 22% of the population spends holidays at the Mediterranean Sea, and UV exposure of the total population from these holidays has increased annually by about 3.3%. Because of the latency period, it is not possible to draw conclusions from the increase in UV exposure and the temporal trends in skin cancer. A longer time series would be necessary to do this. A direct comparison of data from other countries reporting increases in skin cancer does not seem appropriate, as levels of UV exposure vary greatly and such factors as genetic susceptibility are involved.

Austria↗

PubMed1985

Differential effects of exercise on serum lipid and lipoprotein levels seen with changes in body weight. A meta-analysis.

Ninety-five studies conducted between September 1955 and October 1983 measuring changes in human serum lipid and lipoprotein levels in response to exercise training were analyzed using meta-analysis. Change in body weight during exercise training may confound observed serum lipid and lipoprotein level changes; thus, data from these studies were partitioned into those where subjects gained body weight, maintained body weight, or lost body weight. Results showed differential changes in cholesterol, triglyceride, low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol, and cholesterol/high-density lipoprotein-cholesterol levels in the three body-weight categories. Where body weight did not change, cholesterol and LDL-C levels decreased significantly (7.3 mg/dL and 3.3 mg/dL, respectively). Where body weight decreased, cholesterol and LDL-C levels also decreased significantly (13.2 mg/dL and 11.1 mg/dL, respectively). However, with body-weight increase, cholesterol and LDL-C levels increased by 2.9 mg/dL and 3.0 mg/dL, respectively. These results suggest that reductions in cholesterol and LDL-C levels were greatest when exercise training was combined with body-weight losses.

Body Weight↗

PubMed1995

Alpha-2,3 sialylation differentiate the limbal and corneal epithelial cell phenotypes.

PURPOSE: The initial differentiation event for the corneal epithelial cell lineage occurs as the limbally localized stem cells yield, through mitosis, the highly proliferative, transiently amplifying corneal peripheral cells. This differentiation is characterized by the expression of tissue-specific cytokeratins, as well as the loss of alpha-enolase and pigmentation. All these are intracellular events. The aim of this study was to identify and characterize, through lectin analysis, changes in cell surface properties associated with differentiation. METHODS: Cryostat sections of the limbo-corneal area from freshly dissected pigmented rabbit corneas were stained with fluorescent lectins. RESULTS: Peanut lectin (PNA; binds to Ser/Threo-GalNAc-beta-1,3-Gal, if the Gal residue is not sialylated) stained the plasma membrane of all layers of the conjunctiva and limbus but was excluded from corneal cell membranes. Maakia amurensis agglutinin (MAA; binds to sialic acid attached to galactose through alpha-2,3 bonds in either N-glycans or O-glycans) stained exclusively corneal cell plasma membrane. After complete tissue desialylation, all corneal plasma membranes became PNA positive with equal stain intensity across both sides of the limbo-corneal margin. The binding of the agglutinins from Limax flavus (binds unselectively to sialic acid) and Sambucus nigra (binds to sialic acid attached through alpha-2,6 bonds) to the basement membrane displayed a large increase at the corneal side of limbo-corneal demarcation. CONCLUSIONS: Limbal (stem) cells express on the cell surface unsialylated galactose residues that are recognized by PNA and that lack any sialic acid bound through alpha-2,3 bonds. The initial differentiation involves sialylation of these residues and the concurrent appearance of alpha-2,3 sialic acid residues, suggesting expression or activation of alpha-2-3 sialytransferase. Changes in basement membrane composition, charge, or both may underpin this expression.

Animals↗