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Biomedical subjects

H Fischer

Publications and source records attributed to H Fischer.

At least 343 records · Page 19Linked to original sources
PubMed1987

Naloxone in treatment of circulatory shock resistant to conventional therapy.

The effect of naloxone (4.4-5.9 mg i.v.) was evaluated in 10 patients with circulatory shock (sepsis, n = 7; intoxication, n = 1; cardiogenic shock, n = 2) not responding to full conventional therapy. In addition, we measured plasma ACTH and immunoreactive beta-endorphin before and 60 min after administration of naloxone and compared the results with hormone concentrations in 10 intensive care patients without shock. Only in two patient with septic shock a transient increase (duration 15 min and 60 min, respectively) of systolic blood pressure was observed, while naloxone was ineffective in the remaining eight patients. No adverse effects of naloxone were found. Plasma ACTH and immunoreactive beta-endorphin concentrations in patients with shock were not different from those in controls (ACTH, 79 +/- 28 vs 120 +/- 60 pg/ml; immunoreactive beta-endorphin, 952 +/- 262 vs 1,070 +/- 378 pg/ml). Our findings suggest that naloxone in a single dose of 4.4-5.9 mg i.v. does not improve the management of circulatory shock unresponsive to conventional treatment. beta-endorphin seems to play no major role in the hypotension of shock.

Adrenocorticotropic Hormone↗
PubMed1987

A DNA polymerase with unusual properties from the slime mold Physarum polycephalum.

Two forms of a DNA polymerase have been purified from microplasmodia of Physarum polycephalum by poly(ethyleneimine) precipitation and chromatography on DEAE-Sephacel, phosphocellulose, heparin Sepharose, hydroxyapatite, DNA-agarose, blue-Sepharose. They were separated from DNA polymerase alpha on phosphocellulose and from each other on heparin-Sepharose. Form HS1 enzyme was 30-40% pure and form HS2 enzyme 60% with regard to protein contents of the preparations. Form HS2 enzyme was generated from form HS1 enzyme on prolonged standing of enzyme preparations. The DNA polymerases were obtained as complexes of a 60-kDa protein associated with either a 135-kDa (HS1) or a 110-kDa (HS2) DNA-polymerizing polypeptide in a 1:1 molar stoichiometry. The biochemical function of the 60-kDa protein remained unknown. The complexes tended to dissociate during gradient centrifugation and during partition chromatography as well as during polyacrylamide gradient gel electrophoresis under nondenaturing conditions at high dilutions of samples. Both forms existed in plasmodia extracts, their proportions depending on several factors including those which promoted proteolysis. The DNA polymerases resembled eucaryotic DNA polymerase beta by several criteria and were functionally indistinguishable from each other. It is suggested that lower eucaryotes contain repair DNA polymerases, which are similar to those of eubacteria on a molecular mass basis.

Centrifugation, Density Gradient↗
PubMed1987

[Technic of compression bandage].

Pressure bandaging is the basis of any phlebographic therapy. Since a good bandage should fit and hold well, there is need of special bandaging techniques. Any bandage encircling the leg evenly, slackening in pressure from distal to proximal regions and constricting nowhere is considered correct and good. We present our own technique of pressure bandaging, which meets with all these demands.

Bandages↗
PubMed1987

Natural cytotoxic cells from rat liver and spleen kill human glioma cells.

Natural cytotoxic cells from rat spleen and rat liver, (isolated using the collagenase method) were found to be cytotoxic against different lines of human gliomas: T406, T508, T705, HeRo, HeRoCl 1, HeRoCl 8, and HeRo-SV 7/114. After 18 h the lytic units ranged from 75 to 251 in the liver and from 5 to 24 in the spleen. Analyzing the ratio of lysis at 4 h/18 h, it may be concluded that this natural killing is predominantly macrophage (Kupffer cell)-dependent. Lysis by Kupffer cells cannot be increased by transforming glioma cells with SV40. Experiments with SV40-transformed mouse fibroblasts (3T3) and virus-transformed human cell lines (SV80) suggested a "SV40" receptor on Kupffer cells. Thus Kupffer cells have receptors for glioma cells and SV40-dependent membrane structures.

Animals↗
PubMed1987

In vitro model for the response to irradiation of different types of human intracranial tumours.

Twenty-seven human low and high grade gliomas and five meningiomas were cultured in vitro as tumour tissue and/or tumour cells. Cell survival or growth was taken as a measure of radiation response. Astrocytomas II-III and glioblastomas manifested individual patterns of radiosensitivity, ranging from 10 to 90 Gy. Meningiomas did not react. Our findings are consistent with the differences in radiosensitivity of human gliomas experienced clinically and corroborate the validity of the in vitro model.

Brain Neoplasms↗
PubMed1987

Characterization of the protein C activator Protac from the venom of the southern copperhead (Agkistrodon contortrix) snake.

A single chain glycopeptide with a molecular weight of approximately 37,000, an isoelectric point of 3.0 +/- 0.2 and a carbohydrate content of approximately 20% was isolated from the venom of the southern copperhead Agkistrodon contortrix contortrix. It was capable of converting zymogen protein C in plasma of man and various vertebrates into its activated form, a serine proteinase which exerts an anticoagulant effect. Conversion of the zymogen protein C into the active proteinase was demonstrated by measuring the prolongation of the activated partial thromboplastin time due to proteolytic degradation of factors Va and VIIIa by the activation product, as well as by direct measurement of the generated enzyme activity by means of a synthetic chromogenic substrate. Intravenous injection of the venom protein C activator into rabbits caused prolonged activated partial thromboplastin time. Repeated subcutaneous injections led to formation of an antibody which formed, with purified protein C activator as well as with crude A. contortrix venom, a precipitating complex devoid of protein C activator potency. As revealed by activity measurements and by immunodiffusion experiments, the venoms of various A. contortrix, A. bilineatus subspecies contain similar protein C activators.

Animals↗
PubMed1987

Kinetics of humoral response during the acute and the convalescent phase of human trichinosis.

After a common source outbreak of trichinosis in Bitburg, FRG, 107 patients, for whom time and source of infection were precisely known, were prospectively studied for a period of eight months in order to investigate the kinetics of the humoral immune response. Antibodies were assessed by IHA, and by ELISA to quantify IgG, IgM and IgE isotypes. For four different periods of the observation time sensitivity and predictive value of tests to identify acute or convalescent trichinosis were determined. The results demonstrated characteristic kinetics of the different antibody isotypes and varying diagnostic value of the tests. Only IgG-ELISA and double-sandwich IgM-ELISA reliably identified diseased patients shortly after onset of clinical illness and showed a negative predictive value of almost 100% from seven weeks to eight months after infection. IgE antibodies and elevation of total serum IgE occurred only in about 20% of patients and showed no consistent pattern during the course of the disease. Circulating immune complexes were moderately increased four weeks after infection. They rapidly returned to normal values, after the symptoms of the acute phase had disappeared.

Acute Disease↗
PubMed1987

[Field and temperature dependence of contrast in magnetic resonance imaging].

Whereas a change of temperature within the physiological range does not lead to significant contrast alterations in MRI, changing magnetic field strength can lead to drastic alterations in tissue contrast caused by incalculable changes of T1 relaxation. At medium and high fields, longitudinal relaxation is mainly influenced by water content of tissues, at low and ultra-low fields macromolecular structures gain additional influence. Combination of relaxometric measurements with a field cycling device (between 0.0002 and 1.2 T, i.e. 10 kHz and 50 MHz) and imaging experiments at ultra-low, low, and medium fields (between 0.02 and 0.6 T) showed field depending inherent contrast changes with a T1 contrast maximum at medium fields. Induced contrast alterations by application of contrast changing substances in medium and high fields are unpredictable because there is no simple interrelationship between field strength and T1. Furthermore, it could be shown that T1 of pathologically altered tissue is not higher than T1 of normal tissue in any case but can be lower or equal below a certain field strength what contradicts the hypothesis that pathological tissue has a higher T1 than normal tissue.

Animals↗
PubMed1987

[Transient vision loss caused by scandicaine with added arterenol in the excision of basalioma of the side of the nose].

In facial dermatosurgery, the addition of sympathomimetics to local anaesthetics produces a desirable topical effect by creating an almost bloodless operation field due to transitory vasoconstriction. In an 87-year-old woman suffering from a meningioma that had caused blindness of the left eye, a basal-cell carcinoma was removed from the right side of the nose. The local anaesthetic contained noradrenaline at a concentration of 1:50,000. After the operation, the patient complained of headache and a transient loss of vision. We suggest that noradrenaline caused vasoconstriction of the arteria centralis retinae via arterial periorbital anastomoses. Patients with severe vision disorders should be considered a risk group, in whom sympathomimetics should not be added to local anaesthetics used in skin surgery of the middle and upper face.

Aged↗
PubMed1986

[Diagnostic and prognostic significance of so-called rheumatoid vasculitis--2].

51 patients with rheumatoid arthritis and high rheumatoid factors (mean titres 928) underwent examination for the demonstration of an extraarticular organ manifestation within the scope of the cooperation between the Department of Medicine of the Karl-Marx-University Leipzig and the Institute for Rheumatology of the Academy of Medical Sciences of the USSR in Moscow. The frequency of nodous rheumatism (about 60%) is comparable with the frequency of polyneuropathy. In 20% of the patients a systemic muscle atrophy, a hepatomegaly as well as a Raynaud-syndrome were stated. By means of skin biopsy in 28% perivascular infiltrates were found. Altogether in 6 patients (12%) a participation of the lungs and the pleura, respectively, could be proved. Only rarely a clinically manifest heart disease caused by the rheu-we we found an pericardial effusions in 3 cases. In systemic manifestation, such as myositis, participation of the eyes or vasculitis of the digital arteries with necrosis, were only sporadically to be established. Among 22 patients we found an pericardial effusions in 3 cases. In systemic manifestation in most cases increased parameters of activity were found. From the practical point of view apart from increased titers of the rheumatoid titres and circulating immune complexes (C1q-BT) increased concentrations of the C-reactive protein are prognostically significant. The presence of high rheumatoid factor titres alone as well as the isolated presence of rheumatic nodes must not always be connected with an unfavourable prognosis. When severe extraarticular manifestations are present a possibly early, intensive occasionally extracorporeal treatment is indicated.

Adolescent↗
PubMed1986

[Leukocyte function in patients with hyperthyroidism].

In 20 patients with hyperthyroidism the behaviour of the agglomeration of leucocytes as well as of the adhesivity before and after the methimazol therapy was investigated. The agglomeration of leucocytes was directly inhibited neither by the overfunction of the thyroid gland nor by methimazol. By means of a stimulation test an undisturbed ability of leucocytic activation in hyperthyroidism could be proved. The adhesivity at the glass slide, however, was slightly restricted in untreated hyperthyroidism. It normalized under thyrostatic therapy.

Adolescent↗
PubMed1986

Isolation of variants of lymphocytopathic retroviruses from the peripheral blood and cerebrospinal fluid of patients with ARC or AIDS.

LAV/HTLV-III/AAV viruses were isolated from 20 German patients with ARC/AIDS in order to investigate strain variation. Virus was isolated from the peripheral blood and/or cerebrospinal fluid (CSF) in umbilical cord peripheral blood lymphocyte (PBL) cultures. Isolates were identified by their cytopathic effect (CPE), by reverse transcriptase assays on cell-free infected culture supernatant fluid (SNF), and one or more of the following: immunofluorescence assays on infected cells for viral antigen using HTLV-III reference sera, Western blot analysis of cell-free infected culture SNF, electron microscopy of infected cells, and Southern blot restriction analysis and specific HTLV-III probing of DNA extracted from infected cultured PBL. The isolates could be classified into three groups according to differences in growth rate and cytopathic effect: Most showed what was regarded as the typical CPE, while some either grew rapidly and induced a striking CPE and others grew slowly with minimal CPE. In one patient, virus producing typical CPE was isolated from the peripheral blood while the isolate from his filtered cell-free CSF produced atypical slow CPE, suggesting that antigenic variation may occur with persistent infection or that superinfection may occur. Southern blot DNA restriction analysis of the DNA of three selected isolates showed that two of the isolates were similar but that the restriction pattern of all three differed from patterns previously published. Our results supplement the accumulating evidence of genetic variation among LAV/HTLV-III strains. The extent of this variation needs to be evaluated for any effect on the sensitivity of diagnostic tests, on the strategy of vaccine development, on tissue tropism by altering the viral surface receptor-binding sites, and possibly on the development of specific chemotherapy.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Determination of factor X activator in the venom of the saw-scaled viper (Echis carinatus).

Factor X activator in Echis carinatus venom was determined by incubating the zymogen 'factor X' with venom, interrupting the activation process by ethylenediaminetetraacetic acid and measuring the generated proteinase 'factor Xa' by means of a synthetic chromogenic substrate. A comparison of factor X- and prothrombin-activating potencies in E. carinatus venoms of five different geographic origins revealed no correlation between these two procoagulant activities.

Factor X↗
PubMed1986

Chromogenic assay for the prothrombin activator ecarin from the venom of the saw-scaled viper (Echis carinatus).

Ecarin, by limited proteolysis and subsequent autocatalytic reactions, causes the conversion of prothrombin into three products with amidolytic activity: meizothrombin, meizothrombin 1 and lpha-thrombin. Ecarin action may be abolished by ethylenediaminetetraacetic acid and the activity of alpha-thrombin can, with a high degree of selectivity, be inhibited by heparin. Thus, ecarin potency may be assayed by measuring the meizothrombin activity generated by ecarin action on human plasma in the presence of heparin. The chromogenic substrate Tosyl-glycyl-L-prolyl-L-arginine-p-nitroanilide (Chromozym TH) is used in this assay.

Animals↗