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Biomedical subjects

J Bauer

Publications and source records attributed to J Bauer.

At least 415 records · Page 23Linked to original sources
PubMed1992

Isoflurane anaesthesia in the treatment of convulsive status epilepticus. Case report.

Status epilepticus may be resistant to intravenous anticonvulsive drugs. In these cases treatment with the inhalation anaesthetic agent isoflurane may be helpful in the further management. We describe a 35-year-old female patient who suffered from status epilepticus with partial seizures. In spite of therapy with benzodiazepine and phenytoin the status evolved into tonic clonic seizures. Treatment with thiopentone sodium did not stop seizure activity. Anaesthesia with isoflurane (dosage up to 1.5 vol.%) carried out twice within 72 h finally led to a termination of status epilepticus. From our own experience and reports in the literature we conclude that general anaesthesia with isoflurane can and should be used in the treatment of severe status epilepticus that does not respond to intravenous anticonvulsive agents.

Adult↗
PubMed1992

Serum prolactin concentrations and epilepsy. A study which compares healthy subjects with a group of patients in presurgical evaluation and circadian variations with those related to seizures.

In 20 healthy subjects (10 female and 10 male) and 17 patients undergoing presurgical epilepsy evaluation with intracranial EEG electrodes, circadian variations of serum prolactin (PRL) were measured. A comparison between the peak values found in normals with the postictal rises in patients, led us to consider 700 microU/ml to be the threshold of diagnostic value and the observed rises above this level to be all induced by seizures. In order to assess the clinical value of this threshold, PRL was measured postictally in a further 30 patients with epilepsy and in 11 patients with psychogenic seizures. In none of the latter group did PRL rises exceed 700 microU/ml, while they did so in 39% of the complex partial seizures and in 80% of the tonic-clonic seizures. There was no significant difference with respect to sex (a rise over 700 microU/ml in 42% in male and in 55% in female patients). Based on the findings in 17 patients investigated by means of intracranial electrodes, we were not able to establish different criteria for different focus localisations: in 66% of both temporal as well as frontal lobe seizures the 700 microU/ml level was exceeded. As a trend, in the period preceding an epileptic seizure we found a slightly decreasing PRL level, whereas in healthy persons the PRL concentrations gradually increased in the 40 minutes before the maximum spontaneous peak was reached.

Adolescent↗
PubMed1992

Establishment and characterization of a human papillary thyroid carcinoma cell line with oxyphilic differentiation (ONCO-DG 1).

In the present study the establishment and characterization of a new oxyphilic papillary thyroid carcinoma cell line--ONCO-DG1- is given. With immunohistological, histochemical and flow cytometric methods, ONCO-DG 1 cells revealed features of epithelial differentiation. Furthermore the cells formed von Kossa-positive deposits resembling psammoma bodies in monolayer and spheroid culture until late passages. The tumor cell line is now in the 40th subculture. Because of the ability to form multicellular tumor spheroids (MCTS), this cell line is a good model for examining the interaction between thyroid tumor cells and confluent human endothelial cells on extracellular matrix in vitro. It is also suitable for xenotransplantation studies, because it is tumorigenic in NMRI nude mice in vivo.

Animals↗
PubMed1992

[Clinical symptoms and therapy of status epilepticus].

The term "status epilepticus" was first coined in 1824 by Calmeil as this condition had such a poor prognosis. Although still commonly misused today, from the beginning this term actually included all kinds of epileptic seizures, since there are as many types of status epileptici as there are seizure types. Status epileptici are usually triggered by a combination of factors including sleep deprivation, alcohol withdrawal, failure to take medication regularly and fever. In status epilepticus epileptic seizures and EEG discharges initially appear to be no different from isolated seizures. The longer the status epilepticus continues, however, the more atypical the seizures and EEG discharges become. Usually status epilepticus ends gradually. Irreversible damage or fatalities may occur especially in infants or under certain conditions (e.g. long status duration, protracted interval between seizure onset and medical treatment and symptomatic etiology). In most cases benzodiazepines and diphenylhydantoine are the preferred drugs used for treatment.

Anti-Anxiety Agents↗
PubMed1992

Activity of clarithromycin against murine listeriosis.

In-vitro clarithromycin was more active than erythromycin against Listeria monocytogenes. The antibacterial action was bacteristatic. In normal adult mice infected with a virulent strain of L. monocytogenes clarithromycin was also more active than erythromycin. A rapid decrease in viable count was obtained, which was not achieved with erythromycin. Early treatment resulted in a complete abrogation of an immune response to L. monocytogenes. In immunocompromised, congenitally athymic (nude) mice, only a moderate effect on the bacterial numbers was observed, indicating that even in vivo the activity of the macrolides is bacteristatic.

Animals↗
PubMed1992

Erythrocyte K-Cl cotransport: properties and regulation.

Erythrocytes possess a Cl-dependent, Na-independent K transport system cotransporting K and Cl in a 1:1 stoichiometry that is membrane potential independent. This K-Cl cotransporter is stimulated by cell swelling, acidification, Mg depletion, and thiol modification. Cell shrinkage, elevation of cellular divalent ions, thiol alkylation, phosphatase inhibitors, and derivatives of certain loop diuretics and stilbenes are inhibitory. Thus regulation of K-Cl cotransport at the membrane and cytoplasmic levels is highly complex. Basal K-Cl cotransport decreases with cellular maturation, whereas its modes of stimulation and inhibition are variable between species. The physiological inactivation appears to be prevented in low-K animal erythrocytes. In certain human hemoglobinopathies, K-Cl cotransport may be the cause of cellular dehydration and volume decrease. K-Cl cotransport occurs also in nonerythroid cells, such as in epithelial and liver cells of other species. At the threshold of molecular characterization, this comprehensive review places our present understanding of the mechanisms modulating K-Cl cotransport physiologically and pathophysiologically into kinetic and thermodynamic perspectives.

Animals↗
PubMed1992

Linkage between monokine production and regulation of the negative surface charge density of human monocytes.

The regulation of the negative surface charge density of human monocytes was investigated with the help of the synthetic glycolipid analogue BAY R 1005. This compound is incorporated into the outer membrane of isolated monocytes during 24 hours of incubation. After this time the electrophoretic mobility (EM) of monocytes is unchanged at 0.95 x 10(-4) (cm2 V-1 s-1) and remains unchanged even under conditions where non-treated monocytes increase their EM up to 1.1 x 10(-4) (cm2 V-1 s-1). In addition BAY R 1005 stops differentiation of monocytes to macrophages, it triggers monokine production and abolishes monocyte suppressor activity and spreading capability. The results show that BAY R 1005 affects intracellular features. In connection with earlier investigations of the regulation of the negative surface charge density of human monocytes (1,2) the study suggests that monokine production and maintenance of the EM of monocytes are linked.

Cell Differentiation↗
PubMed1992

Evaluation of assay procedures measuring macrophage stimulation by immunomodulators in vitro.

Several assay procedures for measuring the stimulatory effect on macrophages (møs) of bacterial-derived immunomodulators (OM-85, OM-89, OM-163, Laboratoires OM, Meyrin/Geneva, Switzerland) were evaluated with regard to their complexity, speed, and general convenience. To this effect, bone marrow-derived or peritoneal exudate macrophages were exposed to the immunomodulators in vitro, then tested for metabolic stimulation (glucose oxidation through the hexosemonophosphate shunt pathway, synthesis of type E prostaglandins, release of superoxide, and production of L-arginine-derived nitrogen oxidation products), as well as for enhancement of functional activities (production of tumor necrosis factor-alpha, extracellular cytolysis of P815 target cells, and intracellular parasite destruction). All these tests were found to provide adequate measurements of the mø response to the immunomodulators, with significant effects detectable using the compounds in the ng/ml to microgram/ml range. Concomitant incubation with crude macrophage activating factor or with recombinant murine interferon-gamma (IFN-gamma) dramatically increased the sensitivity of møs to the immunomodulators, and was an absolute requirement for induction of mø cytotoxic activities by the bacterial extracts. The measurement of nitrite production by møs exposed to the immunomodulators with or without treatment with 10 U/ml of IFN-gamma was found to be a highly convenient procedure, which correlated well with functional assays.

Adjuvants, Immunologic↗
PubMed1992

Detection of interleukin-6 and alpha 2-macroglobulin immunoreactivity in cortex and hippocampus of Alzheimer's disease patients.

We examined brains from Alzheimer's disease (AD) patients by immunohistochemistry for the presence of protease inhibitors. Immunoreactivity for alpha 2-macroglobulin (alpha 2-M), the most potent of the known human protease inhibitors, was found in a subgroup of cortical and hippocampal AD senile plaques. In addition, large hippocampal neurons in AD brains displayed intracellular alpha 2-M immunoreactivity which was consistently stronger than in normal aged brains. In cultured human cells of neurogenic origin (SH-SY5Y neuroblastoma cells), alpha 2-M synthesis could be strongly induced by the inflammatory cytokine interleukin-6 (IL-6) indicating that human alpha 2-M behaves as an acute-phase protein in the nervous system. Therefore, we also examined AD brains for the presence of IL-6 and found strong immunostaining in and around a subgroup of senile plaques as well as around large cortical neurons. Only very few senile plaques also stained for C-reactive protein, an acute phase protein known to be inducible by IL-6. We propose that the presence of IL-6 and alpha 2-M immunoreactivity in AD brains is functionally linked and that a sequence of immunological events is part of the pathology of AD.

Aged↗
PubMed1992

[Etiology, follow-up and therapy of seizure clusters in temporal lobe epilepsy and catamenial epileptic seizures].

The phenomenon of seizure clustering is still poorly understood. We therefore investigated 192 patients with temporal lobe epilepsies among whom 60 showed clustering of seizures. The percentage of women was significantly higher in the cluster than in the non-cluster group, the history of epilepsy lasted longer and the excess of complex partial seizures over tonic clonic seizures was more prominent in the cluster group. In 46 out of the 60 patients the clustering did not occur initially but developed in the course of the disease. In a particular subgroup the development initiated with isolated tonic clonic seizures, in a later phase complex partial seizures appeared and finally only complex partial seizures remained. This type of history was found significantly more frequent in the cluster than in the non-cluster group (27% versus 7%). It is conjectured that endogenous, as well as exogenous factors, both of them not completely revealed, cause the occurrence of clusters; anticonvulsant drug therapy might even enlarge this trend. Patients with seizure clustering tend to be pharmacoresistant. Chronic therapy with antiepileptic drugs besides intermittent therapy with benzodiazepines may help. A particular type of seizure clustering is observed in catamenial epilepsies where seizures appear in the perimenstrual and/or periovulatory phase of the menstrual hormonal cycle of females. This type of seizure incidence is obviously influenced by hormonal rhythms. Ten patients suffering from catamenial epileptic seizures were therefore treated with a synthetic analogue of GnRH in order to suppress the menstrual hormonal rhythm. As a result 3 patients became seizure free and in 5 patients seizure frequency decreased.

Adolescent↗
PubMed1991

[Rise in serum prolactin concentration after frontal lobe seizures. Possibilities in differential diagnosis of psychogenic seizures].

The prolactin concentration profile over 24 hours was determined in three men, aged 19, 27 and 43 years, who suffered from treatment-resistant complex-partial and (or) grand mal seizures of frontal lobe origin. All three patients were examined in the course of preoperative epilepsy diagnosis, the seizures being classified by video-EEG recordings, including subdural and sphenoidal foramen ovale electrodes. Seizures were recorded in all three patients (4 grand mal; 2 complex-partial), each of them followed by a rise in serum prolactin concentration (over 700 microU/ml). These findings contradict the theory that prolactin concentration rises only after temporal, not after frontal seizures. Knowing the postseizure serum prolactin concentration may help to distinguish frontal epileptic from psychogenic seizures.

Adult↗
PubMed1991

Interleukin-6 and alpha-2-macroglobulin indicate an acute-phase state in Alzheimer's disease cortices.

Recent studies indicated that the formation of a major constituent of Alzheimer's disease (AD) senile plaques, called beta A4-peptide, does not result from normal processing of its precursor, amyloid precursor protein (APP). Since proteolytic cleavage of APP inside its beta A4 sequence was found to be part of APP processing the formation of the beta A4-peptide seems to be prevented under normal conditions. We considered whether in AD one of the endogenous proteinase inhibitors might interfere with APP processing. After we had recently found that cultured human neuronal cells synthesize the most potent of the known human proteinase inhibitors, alpha-2-macroglobulin (alpha 2M), upon stimulation with the inflammatory mediator interleukin-6 (IL-6) we now investigated whether alpha 2M and IL-6 could be detected in AD brains. Here we report that AD cortical senile plaques display strong alpha 2M and IL-6 immunoreactivity while no such immunoreactivity was found in age-matched control brains. Strong perinuclear alpha 2M immunoreactivity in hippocampal CA1 neurons of Alzheimer's disease brains indicates that neuronal cells are the site of alpha 2M synthesis in AD brains. We did not detect elevated IL-6 or alpha 2M levels in the cerebrospinal fluid of AD patients. Our data indicate that a sequence of immunological events which seem to be restricted to the local cortical environment is part of AD pathology.

Acute-Phase Reaction↗
PubMed1991

In-vitro matured human macrophages express Alzheimer's beta A4-amyloid precursor protein indicating synthesis in microglial cells.

Microglia which are consistently associated with Alzheimer's disease (AD) senile plaques are part of the mononuclear phagocyte system. In-vitro matured human monocyte-derived macrophages feature many immunological characteristics of microglia. We found strong constitutive expression of Alzheimer's beta A4-amyloid precursor protein (APP) in human mononuclear phagocytes after terminal in-vitro maturation from monocytes to macrophages. Amyloid has previously been found to be associated with microglia in AD brains, however, it remained unclear whether the material was synthesized in or had been phagocytosed by the cells. The findings presented here support the assumption that brain microglia may contribute to APP synthesis in AD brain.

Amyloid beta-Peptides↗
PubMed1991

Alpha 2-macroglobulin synthesis in interleukin-6-stimulated human neuronal (SH-SY5Y neuroblastoma) cells. Potential significance for the processing of Alzheimer beta-amyloid precursor protein.

Cultured human neuronal (SH-SY5Y neuroblastoma) cells synthesize and secrete the potent protease inhibitor alpha 2-macroglobulin (a2M) upon stimulation with interleukin-6 (IL-6) indicating that alpha 2-macroglobulin behaves as an acute-phase protein in the human central nervous system. Exogenous addition of a2M to the cultured neuronal cells resulted in only a slight inhibition of Alzheimer beta A4-amyloid precursor protein (APP) synthesis, but markedly inhibited its secretion pointing to the possibility that a2M may affect the proteolytic APP processing. Evidence is provided that IL-6 and a2M are involved in Alzheimer's disease pathogenesis.

Alzheimer Disease↗
PubMed1991

Blindness as an ictal phenomenon: investigations with EEG and SPECT in two patients suffering from epilepsy.

Blindness is a rare ictal phenomenon in epileptic seizures. It can occur as an aura, as the seizure itself, or postictally. We investigated two such patients, in one of whom blindness manifested as an aura prior to tonic clonic seizures; the interictal EEG exhibited a spike-wave focus bioccipitally. In the second patient blindness occurred postictally. An ictal SPECT, carried out at the onset of the seizure demonstrated marked hyperperfusion in both occipital regions.

Adult↗
PubMed1991

Interleukin-6 in clinical medicine.

This article covers the basic biological functions of interleukin-6 (IL-6) in man. Three major topics are addressed more closely: the involvement of IL-6 in various disease states, particularly those of hematopoietic origin; the diagnostic usefulness of IL-6 measurements in biological fluids; the possible use of IL-6, IL-6 antagonists or IL-6 derivatives as therapeutic means.

Antineoplastic Agents↗
PubMed1991

Pediatric heart transplantation for congenital heart disease and cardiomyopathy.

Orthotopic heart transplantation has become an accepted therapy for adult patients with end-stage heart disease. In newborns and infants, this procedure is still controversial because of the unknown long-term results and the lack of donor organs. Since March 1988, we have performed orthotopic heart transplantation in 11 infants and children with hypoplastic left heart syndrome (n = 6), cardiomyopathy (n = 4), or congenital endocardial fibroelastosis (n = 1). The smallest infant was 3 days old and weighed 2,650 g. Four of 15 potential donors had to be refused for various medical reasons, and 4 were transferred to our hospital for organ retrieval. Seven hearts were procured remotely. We accepted weight mismatches up to 105% between donor and recipient. There were three perioperative deaths, two in patients 5 and 17 days old with hypoplastic left heart syndrome and 1 in a 2-year-old patient with a dilated cardiomyopathy. All 3 patients had drug-resistant right heart failure. A 2-year-old girl with a dilated cardiomyopathy died 2 months after transplantation owing to severe pulmonary embolism originating from the superior vena cava. The remaining 7 patients are alive and well between 1 month and 31 months after transplantation. Angiographic follow-up has not revealed signs of graft atherosclerosis at 2 years.

Cardiomyopathy, Dilated↗