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F Schaefer

Publications and source records attributed to F Schaefer.

116 records · Page 7Linked to original sources
PubMedDate not supplied

The color-vision approach to emotional space: cortical evoked potential data.

A framework for accounting for emotional phenomena proposed by Sokolov and Boucsein (2000) employs conceptual dimensions that parallel those of hue, brightness, and saturation in color vision. The approach that employs the concepts of emotional quality. intensity, and saturation has been supported by psychophysical emotional scaling data gathered from a few trained observers. We report cortical evoked potential data obtained during the change between different emotions expressed in schematic faces. Twenty-five subjects (13 male, 12 female) were presented with a positive, a negative, and a neutral computer-generated face with random interstimulus intervals in a within-subjects design, together with four meaningful and four meaningless control stimuli made up from the same elements. Frontal, central, parietal, and temporal ERPs were recorded from each hemisphere. Statistically significant outcomes in the P300 and N200 range support the potential fruitfulness of the proposed color-vision-model-based approach to human emotional space.

Adult↗
PubMedDate not supplied

The recovery of cerebrospinal fluid acetylcholinesterase activity in Alzheimer's disease patients after treatment with metrifonate.

We investigated the relationship between peripheral and central cholinesterase (ChE) inhibition levels after chronic treatment of Alzheimer's disease (AD) patients with metrifonate (MTF). In a 6-month, double-blind, placebo-controlled trial in AD patients treated with a weekly 2.9 mg/kg MTF dose, we observed 17.15 +/- 23.43, 66.92 +/- 7.30 and 60.80 +/- 12.20% inhibition (n = 6) of cerebrospinal fluid (CSF) and red blood cell (RBC) acetylcholinesterase (AChE) and plasma butyrylcholinesterase (BuChE), respectively. In another study, AD patients were treated with daily MTF to achieve RBC AChE inhibition levels of 85.90%. The CSF AChE inhibition was 67.93 +/- 13.69% (n = 3) at 3-4 h after the last treatment and 6.62 +/- 9.36% (n = 2) at 8 days after dosing. The recovery half time of CSF AChE was 2.21 +/- 1.22 days. These data show that CSF AChE recovers faster than the peripheral plasma and RBC enzymes. Under conditions of chronic weekly dosing with MTF, RBC AChE inhibition does not reflect CSF, and arguably, brain AChE inhibition. Our data do not support continuous central neuronal AChE inhibition as the mechanism for the long-term efficacy of metrifonate for the treatment of AD.

Acetylcholinesterase↗
PubMedDate not supplied

The use of recombinant human growth hormone in short children with chronic renal failure.

Regulation of the somatotropic axis is altered in chronic renal failure (CRF) resulting in a secondary syndrome of growth hormone (GH) insensitivity. Secretion of growth hormone estimated by deconvolution analysis is low normal in prepubertal patients and reduced in late pubertal children with CRF. Basal and integrated GH serum concentration measured by RIA is increased due to reduced renal metabolic clearance, whereas the fractional urinary excretion is increased due to damage of renal tubular cells. GH receptor mRNA is decreased (rat) and the serum concentration of GH binding protein (BP) activity is low (man). Insulin-like growth factor (IGF)-1 production rate is reduced, whereas serum concentrations of IGFBPs are increased secondary to reduced renal metabolic clearance. This results in a reduction of free, active IGF-1. Treatment with GH induces a rise in serum IGF-1 concentration and normalizes IGF bioactivity. Clinical studies in prepubertal children demonstrated a dramatic rise in height velocity during the first treatment year and to a lesser extent during the following years. In children on conservative treatment prior to dialysis, mean height SDS improved by 1.5 within two years and by 2.0 within four years. Patients with renal allografts responded in a similar way. Age and pretreatment height velocity SDS are confounding variables for the response to GH. Renal function seems not be altered by recombinant human (rh) GH in patients with CRF, and the number of renal allograft rejection crises seems not to be substantially increased under rhGH treatment in allograft recipients.

Child↗
PubMedDate not supplied

Peritoneal loss of growth hormone in children on automated peritoneal dialysis.

OBJECTIVE: To provide quantitative data regarding the daily dialytic loss of growth hormone (GH) in children on peritoneal dialysis (PD). DESIGN: Prospective study involving 24-hour dialysate collections on 3 consecutive days in patients with and without recombinant human GH (rhGH) treatment. SETTING: Single-center outpatient PD program. PATIENTS: Twenty-six children undergoing automated PD (APD): 6 with and 20 without daily rhGH. MAIN OUTCOME MEASURES: Daily peritoneal losses of GH, alpha1-, beta2-microglobulin, transferrin, and albumin. RESULTS: The mean (+/-SEM) daily dialytic GH loss was 2.18+/-0.62 microg/1.73 m2 per day in rhGH-treated patients and 0.42+/-0.28 microg/1.73 m2 per day in untreated patients, (p < 0.05). The intraindividual coefficient of variation of daily GH loss was 65%. The peritoneal loss of GH was positively correlated with that of beta2-microglobulin (r = 0.77, p < 0.001) and alpha1-microglobulin (r = 0.51, p < 0.01). The variability in beta2-microglobulin and alpha1-microglobulin elimination, together with the use of rhGH, explained 66% of the total variability of daily GH excretion. In patients without rhGH therapy, the daily peritoneal GH loss was approximately 0.05% of the estimated daily endogenous production rate based on previous estimates in children with end-stage renal failure. In patients on rhGH therapy, less than 0.1% of the injected rhGH dose was eliminated by dialysis. CONCLUSION: Peritoneal losses of GH in children on APD account only for a minute fraction of endogenous metabolic clearance, and do not explain the variability of the rhGH treatment response. The assessment of dialytic GH elimination may be used to estimate time-integrated mean plasma GH concentrations, and to monitor rhGH treatment compliance.

Albumins↗
PubMedDate not supplied

Peritoneal dialysis-related peritonitis treatment recommendations: 1996 update.

The recommendations provided in this document represent a distillation of various experiences, as well as data obtained from published studies in the setting of substantial changes in antibiotic sensitivity. It is hoped that this revised compilation will provide a basis upon which future developments and advances can be made in the therapeutic approach to infectious complications of peritoneal dialysis.

Anti-Bacterial Agents↗