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Biomedical subjects

H Lechner

Publications and source records attributed to H Lechner.

At least 19 recordsLinked to original sources
PubMed2000

Idiopathic sclerotic inflammation of the orbit with left optic nerve compression in a patient with multifocal fibrosclerosis.

We present the MR imaging findings in a 43-year-old male patient with bilateral idiopathic sclerosing inflammation of the orbit. Bilateral enhancing retrobulbar masses, with concentric compression of the retrobulbar segment of the left optic nerve, were seen. MR imaging proved to be the only means to distinguish between the different intraorbital structures and to determine the exact site of optic nerve compression. To our knowledge, this is the first documented case of MR imaging findings of this entity.

Adult↗
PubMed1998

Status of treatment of vascular dementia.

The therapeutic goal in treating vascular dementia has been based on its presumed association with cerebral arteriosclerosis. Therefore, it is necessary to control risk factors for arteriosclerosis. In this connection, application of platelet-aggregating substances has been used extensively. Promising results have also been observed by altering the hemorheologic profile because hemorheologically active substances may be able to ameliorate the course of vascular dementia. Further improvement could be achieved by application of the HELP system to enhance the effect of hemorheologically active drugs. Using the HELP system, LDL, cholesterol, triglycerides and fibrinogen can be lowered considerably and may result in clinical improvement or slowing of the progression of vascular dementia.

Anticoagulants↗
PubMed1997

[Prevalence and risk factors in the population of Graz (Austrian Stroke Prevention Study)].

The Austrian Stroke Prevention Study recruited 1960 randomly selected subjects aged 50 to 75 years during a 3-year period of enrollment. The response rate of the study was 32.4%. A telephone interview with 200 randomly selected non-responders yielded no differences to responders regarding the frequency of major vascular risk factors known to the subjects. Besides demographics, the study assessed arterial hypertension, diabetes mellitus, cardiac disease, smoking, a complete lipid status including the apolipoprotein-E genotype, serum fibrinogen and anticardiolipin antibodies as well as various natural antioxidants such as vitamins A, C, E and beta-carotene. Arterial hypertension, diabetes mellitus, cardiac disease and hypercholesterolemia > 200 mg/dl were strikingly common and occurred in 38%, 7.6%, 32% and 76%, respectively. Suboptimal plasma concentrations of vitamin A, E, and beta-carotene were noted in 77.2%, 56.1% and in 53.2% of study participants. The rate of treatment of major risk factors known to the subjects prior to study entry were 60.3% and 70% for arterial hypertension and diabetes mellitus, but only 37.1% and 6.3% for cardiac disease and hypercholesterolemia > 250 mg/dl. Diet was commonly used to treat diabetes but was almost neglected in the treatment of other vascular risk factors. These data provide an orientation on the prevalence of risk factors and the use of primary preventive measures for stroke treatment in our community.

Adult↗
PubMed1996

Regulation of CD95 (APO-1) expression and the induction of apoptosis in human T cells: changes in old age.

CD95 (APO-1) is a member of the TNF/nerve growth factor receptor superfamily, which is expressed on the surface of different types of cells. Cross-linking of CD95 leads to the induction of apoptosis. This may be of importance in many physiological systems, but seems to play a special role for the maintenance of immunological homeostasis. In view of the known decline of immune function in old age it seemed of interest to study the expression and inducibility of CD95 in peripheral blood T lymphocytes from young and old healthy subjects selected according to the guidelines laid down in the Senieur protocol of the European Community's Concerted Action Programme on Aging. Resting T cells did not express CD95. T cell activation by anti-CD3 monoclonal antibody (OKT3) did, however, lead to a rapid increase in the number of CD95 expressing cells. This increase was slower and less pronounced in old healthy subjects than in young ones. The activation-induced increase in CD95 expression was followed by a decrease, which was observed in both age groups, but was less pronounced in old subjects. Under long-term culture conditions T cell lines derived from both young and old individuals progressively lost the capacity to decrease the expression of CD95 at the end of their activation cycle and an increasing susceptibility to activation-driven programmed cell death was noted. The latter change was more pronounced in T cell lines derived from aged donors. The results suggest that a lowered sensitivity in the regulation of CD95 as well as an increased susceptibility to apoptosis-inducing mechanisms during clonal expansion are features of T cell senescence.

Adult↗
PubMed1995

Magnetic resonance imaging cerebral abnormalities and neuropsychologic test performance in elderly hypertensive subjects. A case-control study.

OBJECTIVE: To search for a morphologic basis of cognitive impairment possibly associated with arterial hypertension using magnetic resonance imaging and a demanding neuropsychologic test battery. DESIGN: Case-control comparison with age, length of education, presence of diabetes, and presence of cardiac disease as matching criteria. SETTING: Austrian Stroke Prevention Study. SUBJECTS: A total of 89 hypertensive subjects and 89 control subjects from a subset of 272 volunteers with no neurologic symptoms undergoing extensive diagnostic workup in a large-scale stroke prevention study among randomly selected elderly community members. MAIN OUTCOME MEASURES: Focal brain abnormalities and size of ventricles and cortical sulci as assessed by magnetic resonance imaging and neuropsychological test scores. RESULTS: Hypertensive subjects more commonly showed areas of white matter hyperintensity and moderately severe ventricular enlargement compared with controls. While no differences were noted between the investigational groups in test results of memory capacity and conceptualization, hypertensive subjects tended to perform worse when assessed for attentional and visuopractical skills. These differences became significant when comparing the brain-damaged subsets of patients and controls with their counterparts without cerebral changes. The pattern and extent of neuropsychologic deficits was similar in hypertensive and normotensive subjects with abnormal magnetic resonance imaging scans. CONCLUSION: Our data strongly suggest the high rate of brain abnormalities among hypertensive subjects as the cause of their subtle neuropsychological dysfunction.

Aged↗
PubMed1995

EEG, CT and neurosonographic findings in patients with postischemic seizures.

Seventy-two patients with postischemic seizures were evaluated with electroencephalography (EEG), computerized tomography (CT) and neurosonography. There were 24% early-onset and 76% late-onset initial seizures. Early-onset seizure was more likely to be simple partial (53%), whereas late-onset seizure was more likely to be primarily generalized (56%). 76% early-onset and 80% late-onset seizures were single. Status epilepticus was more frequent in early-onset that late-onset seizures (p = 0.023). The possibility of recurrence was greater in late-onset than early-onset seizures (p < 0.001). 88% patients had EEG abnormalities, and the most common finding was focal slowing. 75% patients had cerebral infarctions on CT scan, and the majority of them involved cortex. 89% postischemic seizures had carotid lesions which mostly were carotid plaques < 50%. We failed to find these data to be useful in predicting the time of onset of initial seizures after acute ischemic stroke and recurrence.

Adult↗
PubMed1995

Magnetic resonance imaging and spectroscopy findings after focal status epilepticus.

The etiology of cerebral abnormalities after focal status epilepticus (SE) is unknown. Possible causes include hypoxia and the excessive release of excitatory amino acids. Magnetic resonance imaging (MRI) of a 21-year-old patient with "cryptogenic" continuous motor seizures showed swelling and signal hyperintensity of the contralateral parietotemporal cortex, the thalamus, and the ipsilateral cerebellum on T2-weighted images. These regions are connected by glutamatergic pathways. Proton magnetic resonance spectroscopy (MRS) of the cortical lesion yielded a signal peak at the resonance frequency of 2.29 ppm, suggesting a focal increase of glutamate or its degradation product glutamine. At 3-month follow-up, structural alterations had disappeared, but the N-acetyl-aspartate/choline ratio was still reduced in the previously abnormal area. These findings are the first to demonstrate the contribution of MRS to pathophysiologic studies of focal SE in humans and, in combination with the pattern of imaging abnormalities, support a major role of glutamate for seizure-related brain damage.

Adult↗
PubMed1995

[Sleep apnea as a risk factor].

Sleep apnea and snoring are widely discussed as risk factors for internal and neurological diseases. The prevalence of snoring in an Austrian population survey is about 27.2% (males 36.5%, females 18.9%), and that of apnea (respectively irregularity and/or cessation of breathing) about 8.5% (31% of all snorers). Clinical symptoms like naps, daytime sleepiness, unquiet sleep, hypertonia, headache in the morning and psychological symptoms may be characteristics of sleep apnea. They should lead to further diagnosis and removal of this risk factor for ischemic heart disease and stroke.

Adolescent↗
PubMed1994

Hyperthermia inhibits proliferation and stimulates the expression of differentiation markers in cultured thyroid carcinoma cells.

In the last two decades hyperthermia has increasingly been used as adjuvant therapy for the treatment of malignant tumours. The effects of heat were therefore analysed on cultured thyroid epithelial cells from patients with thyroid cancer and from non-malignant control thyroids. Purified thyroid cells were subjected to heat treatment (42.5 degrees C; 90 min). After 24 h [3H]thymidine incorporation was assessed and the expression of heat shock protein 72 (hsp72), thyroglobulin, CD54 (ICAM-I) and MHC class-Il were analysed by immunofluorescence staining. Additionally mRNA analysis was performed by Northern blotting. Whereas hyperthermia inhibited the proliferation of thyroid cells, it significantly increased the expression of hsp72, thyroglobulin, CD54 and HLA-DR (P < 0.05). Our results suggest that hyperthermia may suppress growth while supporting differentiation and immune recognition in thyroid cancer. It may therefore be beneficial as a treatment for patients with thyroid carcinoma.

Adenocarcinoma, Follicular↗
PubMed1994

Extracorporeal fibrinogen and platelet precipitation as a new haemorheological treatment for acute stroke.

In thromboembolic brain infarctions high fibrinogen levels are associated with an increase of both plasma and whole blood viscosity as well as increased aggregability of blood cells. This decreases cerebral perfusion and might reduce blood flow in the penumbra surrounding infarction. An important goal in the treatment of acute cerebral infarction is to reduce fibrinogen and thereby improve the haemorheological state. Heparin-induced extracorporeal low-density lipoprotein/fibrinogen precipitation (HELP) appears to be successful in achieving this. Such treatment reduces lipid fractions, including total cholesterol, low-density lipoproteins (LDL) and triglycerides (p < 0.0001 each), as well as fibrinogen (p < 0.0001) in a safe and efficacious manner. Whole blood and plasma viscosity are also improved when measured by oscillo-rheometry. Furthermore, the number and aggregation tendency of blood cells is influenced positively as determined by Coulter counting and aggregometry. HELP improves the haemorheological profile to a degree which has not been achieved by haemorheologically active substances.

Acute Disease↗
PubMed1994

Assessment of cerebrovascular risk profiles in healthy persons: definition of research goals and the Austrian Stroke Prevention Study (ASPS).

The advent of new laboratory methods and noninvasive imaging modalities has extended the diagnostic possibilities in normal individuals. This article elaborates the new options for the assessment of stroke risk offered by these techniques. In this context we present the Austrian Stroke Prevention Study, which is the first prospective long-term investigation of normals that includes Doppler sonography, magnetic resonance imaging and single photon emission computed tomography. The design, utility and limitations of this study are discussed.

Aged↗
PubMed1994

EEG mapping--a new way of monitoring in epilepsy.

A method for comparison of EEG mapping findings on the basis of numeric data, i.e. the numeric power values measured at the electrode sites for each frequency band, is described. Examples for the clinical use of comparison studies in epileptic patients are given. The problems regarding methodological issues are discussed.

Adult↗