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Biomedical subjects

C Lauer

Publications and source records attributed to C Lauer.

At least 37 records · Page 2Linked to original sources
PubMed1989

The effect of neuroendocrine secretion on brain morphology and EEG sleep in patients with eating disorders.

Neuroendocrine disturbances [low plasma levels of triiodothyronine (T3), high plasma concentrations of cortisol], morphological brain alterations [enlarged external cerebrospinal fluid (CSF) spaces, dilatation of the ventricles] and altered sleep patterns [fragmented sleep continuity, a reduction of slow wave sleep (SWS) or REM sleep] have been described in patients with anorexia nervosa and bulimia nervosa. The present study investigates to what degree these disturbances interact with each other. In ten anorexic and five bulimic patients cranial computed tomography (CT) to estimate the size of the CSF spaces, blood sampling to measure cortisol and T3 plasma concentrations, and all-night polysomnography were performed. In comparison with patients with normal CT scans, the patients displaying enlarged CSF spaces spent more time in SWS, and the duration of REM sleep was reduced. In the whole sample, a negative correlation was found between the amount of REM sleep and cortisol, whereas a positive association was found between the amount of REM sleep and the T3 level. In addition, the degree of brain shrinkage correlated positively with cortisol and negatively with T3. On the basis of these results, it can be assumed that in patients with eating disorders the disease process with its neuroendocrine alterations affects brain morphology as well as EEG sleep.

Brain↗
PubMed1989

Structural brain abnormalities in patients with bulimia nervosa.

Computed tomographic (CT) brain scans were performed in 50 inpatients with bulimia nervosa, 50 anorectic inpatients, and 50 age-matched control subjects. A number of patients with bulimia nervosa had enlarged ventricles and/or sulcal widening, but the degree and frequency of ventricular dilatation and sulcal widening were not so pronounced as in patients with anorexia nervosa. As the bulimic patients were of normal body weight, the CT abnormalities cannot be attributed to emaciation, which has often been suggested as the cause of abnormalities found in anorectic patients. Since many bulimic patients repeatedly attempt to lose weight by going on restrictive diets, the morphological brain alterations may reflect the endocrine and metabolic reactions to starvation--regardless of whether starvation has led to emaciation, as in the case of anorexia nervosa, or only counterbalanced the binges of high-caloric food. This assumption is supported by the finding that in both bulimic and anorectic patients ventricular size is inversely correlated with the plasma levels of triiodothyronine, a low concentration of which is an indicator for starvation.

3-Hydroxybutyric Acid↗
PubMed1989

Afferent arteriolar C3 disease--a distinct pathological entity.

Afferent arteriolar C3 deposition was the sole histological abnormality in 79 and the major histological abnormality in an additional 39 of 959 renal biopsies performed over a 10-year period. Of these 79 patients, hematuria was the presenting symptom in 90%, with coincident loin pain in 49%. Urine microscopy of asymptomatic first-degree relatives revealed hematuria in 44% of children and siblings and 54% of parents, suggesting autosomal dominant inheritance. Arteriolar C3 deposition was confirmed by biopsy in four asymptomatic relatives with hematuria. Generalized thinning of glomerular basement membrane (less than 200 nm) was observed in five patients and focal thinning was observed in six patients with coincident afferent arteriolar C3 deposition. Seven other patients were identified as having generalized thinning of glomerular basement membrane in the absence of afferent arteriolar C3 deposition. Renal function was stable and similar in all groups studied over 37.9 +/- 23.7 months. No difference in clinical presentation or urinary abnormalities was evident between the groups. No arteriolar C3 deposition was evident in eight autopsy specimens with no known renal disease. It was concluded that afferent arteriolar C3 deposition is a marker of a distinct hereditary pathological entity, with differentiation from thin basement membrane disease not possible on clinical grounds. The medium- and long-term prognoses with respect to renal function are excellent.

Adolescent↗
PubMed1989

[Sleep in anorexia nervosa, bulimia nervosa and depressive diseases: a polysomnographic comparative study].

All-night EEG sleep in 20 anorexics, 10 bulimics, 10 endogenous depressives, and in 10 healthy subjects (all age matched) was compared. In addition, the REM sleep-induction-test was performed in 12 patients with an eating disorder, 7 depressives, and 12 controls by application of the cholinergic agent RS 86. During baseline night, EEG-sleep parameters, especially REM latency, did not differ between the patients and the controls, except for the phasic components of REM sleep (REM density) that were increased in the depressive patients. The frequency of shortened REM latencies, however, was significantly higher in the depressed patients. These observations indicate that in some of the young depressives the disturbance of the REM sleep regulating transmitter system is already present to a similar degree as it is assumed in elderly depressives. After the application of RS 86, REM latency was shortened in all groups under investigation. However, the REM sleep inducing effect of RS 86 was significantly more pronounced in the depressives when compared with both the eating disorder patients and the controls. In the latter two samples, the shortening of REM latency was similar. Furthermore, the eating disorder patients with a concomitant major depression reacted similar to RS 86 as the non-depressed eating disorder patients and the control subjects. Whereas baseline EEG-sleep did not differ significantly among eating disorder patients, young depressives, and healthy subjects, the REM sleep inducing effect of the cholinergic agent RS 86 clearly distinguished between the depressives and both the patients suffering from eating disorders and the controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[Brain structure and brain function in anorexia nervosa: a computerized tomography study].

Cranial computed tomography (CT) was performed in 12 patients with anorexia nervosa revealing that the majority of the patients displayed ventricular dilatation and/or sulcal widening. In six patients re-examined these structural brain alterations showed a strong trendency towards normalization after weight gain. With the intention of finding a functional correlate of the CT abnormalities, the regional cerebral blood flow (rCBF) was measured at admission and once again after weight gain and compared with the flow rates of a healthy control group. The mean flow rates assessed at the first examination did not significantly differ from those assessed at the second examination and from those of a control group. Thus, despite the CT findings of structural brain abnormalities, the measurement of the regional cerebral blood flow gave no hint of a reduced functioning of certain brain areas in anorexia nervosa.

Adolescent↗
PubMed1988

Endocrine, metabolic, and cranial computed tomographic findings in anorexia nervosa.

Computerized tomographic brain scans were completed in 50 inpatients with anorexia nervosa and were compared with an age- and sex-matched control group. Seventy percent of the anorectic patients displayed enlarged lateral ventricles. There was a close link between ventricular size and low weight, but not between ventricular size and duration of the eating disorder. In addition, sulcal widening was observed more frequently in patients with enlarged ventricles than in patients without these structural changes. After weight gain, a statistically significant decrease in ventricular dilatation could be observed even when mean ventricular size still far exceeded that of the control subjects. The analysis of the endocrine and metabolic parameters, known to be indicators for the process of starvation, revealed a significant inverse correlation between triiodothyronine and ventricular size. Various possible pathogenetic mechanisms for the morphological brain alterations in patients with eating disorders are discussed.

3-Hydroxybutyric Acid↗
PubMed1988

Influence of the cholinergic agonist RS 86 on normal sleep: sex and age effects.

In 36 healthy control subjects (21 females, 15 males; age range 18-65 years; mean age 41.8 years, SD 15.6 years), a bedtime dose of 1.5 mg RS 86, an orally acting cholinergic agonist, shortened rapid eye movement (REM) latency, increased REM sleep, and decreased slow-wave sleep. Six of the subjects (greater than 40 years old) even displayed sleep-onset REM periods after the drug. Results of the present study agree well with those of studies using other cholinomimetics (i.e., physostigmine, arecholine) and confirm the importance of the cholinergic system for REM sleep regulation. Since RS 86 mimicked some of the REM sleep abnormalities specific for patients with depressive disorders, the cholinergic system may play a role in the pathogenesis and pathophysiology of depressive diseases.

Adolescent↗
PubMed1988

EEG sleep and the cholinergic REM induction test in anorexic and bulimic patients.

The electroencephalographic (EEG) sleep of 20 anorexic patients, 10 bulimic patients, and 10 age-matched healthy controls was studied. In addition, six anorexic patients and six bulimic patients had a cholinergic rapid eye movement (REM) sleep induction test (RIT) performed with the cholinergic agent RS 86. The three samples showed no major differences in sleep patterns. The same held true when attention was focused on patients who additionally met DSM-III criteria for major depression. The RIT results were similar in the patients with eating disorders and in controls, but differed from those reported in depressives. Therefore, the present study found no hints of depression-like sleep patterns in patients with eating disorders.

Adult↗
PubMed1988

Sustained function of normoxic hearts depleted in ATP and phosphocreatine: a 31P-NMR study.

A model of high-energy phosphate depletion was developed in the normoxic isovolumic rat heart perfused with acetate, 2-deoxy-D-glucose (2DG), and insulin. Intracellular phosphorylation of 2DG abstracts phosphorus from its normal pathways. This results in a decrease of high-energy phosphates without any increase in Pi. During the first 15 min of 2DG phosphorylation, the changes in ATP, Pi, and intracellular pH (pHi) were slight, and work was unaltered, although phosphocreatine (PCr) concentration dropped by 50%. After 45 min, the heart reached a new steady state characterized by a drastic reduction in both PCr and ATP: PCr was 15% of control, and in most hearts ATP became invisible on the nuclear magnetic resonance (NMR) spectra. Nevertheless, the heart still developed 65% of its original systolic pressure, whereas diastolic pressure was unchanged. Oxygen consumption per unit work remained constant during 2DG perfusion. This is, to our knowledge, the first experimental model of sustained cardiac contractility at such low contents of both ATP and PCr. However, our results are compatible with present knowledge of the cytosolic energy transfer by PCr and of the control of force in myofilaments.

Adenine Nucleotides↗
PubMed1987

Reversible MM-creatine kinase binding to cardiac myofibrils.

Skinned rat papillary muscles and purified preparations of rat cardiac myofibrils were used to study the nature of the interaction of creatine kinase with cardiac myofibrils. High activity of creatine kinase (2 IU/mg protein in fibers and 0.9 IU/mg in purified myofibrils) was due mostly to reversibly bound enzyme. This activity could be removed and rebound. The process of creatine kinase rebinding was characterized by apparent Km value of 0.14 mg/ml (approximately equal to 2 X 10(6) M). Rebinding of creatine kinase to cardiac myofibrils restored the phenomenon of functional compartmentation of adenine nucleotides in myofibrillar space and restored the ability of phosphocreatine to decrease the rigor tension in the presence of MgADP. The physiological experiments with quick length changes showed that rebinding of creatine kinase to skinned papillary muscle also restored Ca sensitivity, increased maximal tension development, decreased stiffness, and restored the tension recovery after quick length changes in muscle under condition of inhibition of endogenous creatine kinase by 1-fluoro-2,4-dinitrobenzene. It is concluded that creatine kinase reversibly bound to cardiac myofibrils is involved in the energy supply for cardiac contraction.

Adenine Nucleotides↗
PubMed1987

Sleep and dreams in eating disorders.

The results of several studies on sleep EEG and dreams in patients with eating disorders are presented and compared with the data obtained in patients with a major depression. The sleep pattern, which is characteristic of depression, could not be found in the eating disorder group. Regarding the cholinergic REM induction test, the depressive displayed a pronounced shortening of REM sleep latency. However, this biological marker, indicating a cholinergic hyperactivity in depression, could not be observed in patients with eating disorders. The content analysis of laboratory-recorded dreams yielded several differences between depression and eating disorders and also, more subtle, between anorexia and bulimia.

Anorexia Nervosa↗
PubMed1987

Hormonal and metabolic mechanisms in the development of cerebral pseudoatrophy in eating disorders.

Cranial computed tomography (CT) examinations performed on patients with schizophrenia, affective disorders or on patients with anorexia and bulimia nervosa revealed morphological brain alterations. In patients with eating disorders these structural changes were characterized by enlarged ventricles and sulci. Malnourishment-induced hormonal and metabolic disturbances may be responsible for this morphological brain alteration which, due to its reversibility after clinical remission, is frequently called 'pseudoatrophy'. As patients with alcohol dependency also display a cerebral pseudoatrophy, the search for similarities between alcoholics and patients with eating disorders may help to elucidate some of the pathogenetic factors which cause the CT findings in patients with different psychiatric or psychosomatic disorders.

Anorexia Nervosa↗
PubMed1986

Comparative effects of the ionophore A23187 on the mechanical responses of muscle in normal Pietrain pigs and pigs with malignant hyperthermia.

Since increased intracellular Ca2+ is believed to be the main factor causing skeletal muscle contracture in human and porcine malignant hyperthermia, the potential effects of the ionophore A23187, which enhances intracytoplasmic Ca2+, were investigated in Pietrain pig muscles. These effects were compared with those of caffeine, known to induce dose-dependent contracture in vitro in isolated muscle from human subjects with malignant hyperthermia. For this purpose, the mechanical and biochemical actions of caffeine and A23187 were tested in intercostal muscle biopsies from 10 normal pigs and 10 with malignant hyperthermia. The results show that A23187 allowed very clear differentiation between the muscles of normal and pathological animals. In view of the wide spectrum of drug sensitivity characterizing subjects with malignant hyperthermia, it is suggested that exposure to A23187 be added to the halothane and caffeine tests currently used to detect this disease.

Animals↗
PubMed1984

Fulminant hepatic failure due to allopurinol.

A 58-year-old Chinese woman was admitted to hospital with a presumed hypersensitivity reaction to allopurinol. Her illness was characterised by high fever, eosinophilia, exfoliative dermatitis and jaundice. She developed fulminant hepatic failure and septicemia with a fatal outcome. Clinical details are presented and the possible relationship of allopurinol hypersensitivity to renal impairment is discussed.

Allopurinol↗