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Biomedical subjects

M Linden

Publications and source records attributed to M Linden.

At least 181 records · Page 10Linked to original sources
PubMed1988

[Definition, significance and measurement of disease concepts of patients. The Disease Concept Scale for schizophrenic patients].

Illness concepts represent cognitive interpretations, explanations and predictions of health status. Illness concepts are a consequence and an expression of the patient's cultural background, view of the world, value system, way of living, and personal life experiences. Illness concepts are significant in that they influence patient's informed consent and compliance behavior. Illness concepts have been formulated in phenomenological-descriptive, formal-structural and psychological approaches. Based on these alternative conceptualizations, a scale was developed to measure seven dimensions of illness concepts. including trust in medication, trust in the treating physician, negative treatment expectations, guilt, chance control, susceptibility, and idiosyncratic assumptions. The reliability and validity of the scale (KK-scale) was tested in a group of schizophrenic patients in different treatment settings. The psychometric properties of the scale were found to be satisfactory. Support for the discriminant validity of the scale was found in relation to patient's age, education, sex, and compliance treatment institution.

Adolescent↗
PubMed1988

[Incidence and therapeutic relevance of the adverse effects of antidepressive agents within the scope of ambulatory neurologic treatment].

Within a postmarketing drug surveillance study the incidence and relevance of ADRs leading to drug discontinuation in therapy of depressed outpatients were examined. In addition, corresponding drug prescribing patterns of patients under routine treatment conditions were recorded. It was found that most psychiatric outpatients were able to identify common ADRs and to differentiate them from the underlying illnesses and comedication. Low-dose therapy was confirmed as routine treatment in the majority of psychiatric outpatients. No differences regarding age, sex, and dosage could be found between patients with further drug intake and those who stopped their antidepressant medication because of ADRs. Such events had been recorded in 11.5% of patients with first prescriptions made by the treating physicians in a monitoring of three months. However, only 0.3% of patients on long-term therapy (that had been initiated at treatment terms preceding the monitoring period) experienced an ADR indicating a decreased risk for drug discontinuation (because of ADR) the longer the patient was on treatment. Knowing ADR(-profiles) of prescribed drugs by treating psychiatrist may aid the treatment of compliance or prevention of ADRs.

Antidepressive Agents↗
PubMed1988

Effects of oral N-acetylcysteine on cell content and macrophage function in bronchoalveolar lavage from healthy smokers.

Bronchoalveolar lavage (BAL) was performed in fourteen healthy non-smokers and eleven healthy smokers. In smokers BAL was performed before and after eight weeks' treatment with N-acetylcysteine (NAC; 200 mg t.i.d.). Cell number, composition and viability were determined in the BAL fluid. Alveolar macrophages (AMs) were cultured before examination of their phagocytic capacity and their ability to produce leukotriene B4 (LTB4). BAL fluid from smokers contained more cells than that from non-smokers (p less than 0.001). This was mainly attributable to increases in both proportion and absolute number of AMs (p less than 0.001) and to an increase in absolute number of neutrophils (p less than 0.05). However, there was a decrease in proportion of lymphocytes in BAL fluid from smokers (p less than 0.001). Phagocytic capacity of adherent cells and capacity of AMs to generate LTB4 after stimulation with opsonized zymosan (OZy) were decreased in smokers (p less than 0.05 and p less than 0.01 respectively). NAC treatment of smokers did not affect cell number but resulted in an increased proportion of lymphocytes in BAL fluid (p less than 0.05). The phagocytic capacity of AMs was not significantly altered but was improved in five of eleven smokers after NAC treatment. NAC also enhanced the decreased LTB4 secretion by smokers' AMs (p less than 0.05). We conclude that smoking leads to reduced phagocytic capacity and LTB4 secretion of AMs and that oral NAC treatment may improve the function of AMs.

Acetylcysteine↗
PubMed1988

Early phase-II semi double-blind study of the new alkaline propanolamine derivative enciprazine (short communication).

A new alkaline propanolamine derivative, enciprazine, was tested in an early phase-II semi double-blind placebo-controlled A-B-A design to verify the hypothesis that the substance may have tranquilizing properties. No sedative or anxiolytic effect comparable to minor or major tranquilizers could be observed. According to clinical impression some patients showed an improved goal orientation and self-control which could be effects worth to be followed up.

Adult↗
PubMed1987

Subfractionation of the outer membrane of rat brain mitochondria: evidence for the existence of a domain containing the porin-hexokinase complex.

Isolated and well-characterized rat brain nonsynaptic mitochondria were subfractionated by digitonin. Antibodies to a uniquely outer membrane protein, porin, have allowed us to use this protein for the first time as an outer membrane marker in brain. Hexokinase, which binds to porin, was also measured. Based upon the sequential release of these and other marker enzymes with increasing concentrations of digitonin, three outer membrane domains have been identified. Two populations of porin were found by this treatment. The most plausible interpretation of our results is that the two porin populations exist in different membrane environments with regard to cholesterol. One of these populations binds most of the hexokinase and appears to be associated with the inner membrane. It is proposed that the porin-hexokinase complex in brain mitochondria is located in a cholesterol-free membrane domain together with inner membrane components. This domain has the features of contact points which have been visualized by electron microscopy.

Animals↗
PubMed1987

[The bioavailability of midodrin and alpha-2,5-dimethoxyphenyl-beta-aminoethanol hydrochloride].

The pharmacokinetics of midodrin (alpha-2,5-dimethoxyphenyl-beta-glycinamidoethanol hydrochloride, ST 1085) and its main metabolite ST 1059 (alpha-2,5-dimethoxyphenyl-beta-aminoethanol hydrochloride) have been investigated in 12 male healthy volunteers. 2.5 mg midodrin hydrochloride were applied intravenously, as drinking solution or as tablet (Gutron) according to a randomized cross-over design. Plasma and urine samples collected up to 24 h after application were analyzed by high-performance liquid chromatography with fluorescence detection. The mean maximum concentration in plasma for midodrin was ca. 10 ng/ml 20-30 min after oral administration, for ST 1059 ca. 5 ng/ml after 1 h. Midodrin was eliminated with a terminal half-life of 0.5 h. The half-life of ST 1059 was determined to be 3 h. The mean area under the plasma-level vs. time curve (AUC) of ST 1059 after administration of 2.5 mg midodrin i.v. was 28.7 ng X h/ml, and as drinking solution or as tablet 25.7 and 25.6 ng X h/ml, respectively. The data of 10 volunteers could be used for the calculations of the bioavailability of ST 1059 by the AUC. Assuming an interval of equivalence of 0.75-1.25 because of the relatively small number of volunteers, the three galenical formulations are considered to be equivalent.

Administration, Oral↗
PubMed1987

Human alveolar macrophages from smokers have an impaired capacity to secrete LTB4 but not other chemotactic factors.

The function of alveolar macrophages (AM phi s) was studied in terms of the secretion of various chemotactic factors. Human AM phi s were obtained by BAL from healthy non-smokers and smokers. One of the chemotactic factors was LTB4, an arachidonic acid metabolite of the lipoxygenase pathway. The amount of LTB4 was determined in culture medium, in cell homogenate and in BAL-fluid. The total chemotactic activity for neutrophils was measured in culture medium and in BAL-fluid. AM phi s from smokers showed an impaired secretion of LTB4. The spontaneous secretion in vitro was inhibited by 90% (p less than 0.05) and the stimulated one was blocked by 84% (p less than 0.05). This impairment was not followed by a decrease in total chemotactic activity, indicating the existence of other chemotactic factors than LTB4. Preliminary characterization of the chemotactic activity by gel filtration demonstrated at least four different chemotactic factors. Budesonide inhibited both the release of LTB4 and the total chemotactic activity in medium from stimulated AM phi s.

Bronchoalveolar Lavage Fluid↗
PubMed1987

[Negative vs. positive therapy expectations and compliance vs. noncompliance].

The problem of compliance is compared against that of noncompliance, these two phenomena being fundamentally different from each other and depending also on different factors. A cross-sectional investigation of schizophrenic patients showed that compliant patients do not differ from the noncompliant ones with regard to the number of subjectively experienced negative drug effects but with regard to the number of subjectively experienced positive drug effects. These findings are interpreted in such a manner that patients are less likely to be prevented from complying with a treatment by the negative effects of that treatment and are more likely to cooperate because of positive therapy expectations. The question as to what represents positive therapy experiences, is discussed, as well as the problem of promoting an understanding between the physician and the patient in respect of this important aspect of therapy.

Adult↗
PubMed1986

Stimuli-induced superoxide radical generation in vitro by human alveolar macrophages from smokers: modulation by N-acetylcysteine treatment in vivo.

Bronchoalveolar lavage (BAL) was performed on nine healthy nonsmoking subjects and on 11 healthy smokers; in the last mentioned group lavage was performed before and after eight weeks treatment with N-acetylcysteine (NAC; 200 mg t.i.d.). The BAL cells were cultured for 2 h or overnight. Adherent cells were examined for their capacity to generate superoxide radicals (determined by superoxide dismutase (SOD)-inhibitable cytochrome C-reduction) at stimulation with phorbol 12-myristate 13-acetate (PMA), serum-treated zymosan (STZ), the calcium ionophore A23187, or the chemotactic tripeptide formyl-methionylleucylphenylalanine (FMLP). Cells from nonsmokers responded with a very low degree of O(2)-generation to any of the stimuli employed whether cultured for 2 h or overnight. Cells from smokers also responded with low O(2)-generation after 2 h of culture. However, cells from smokers cultured overnight responded with marked O(2)-generation to PMA and STZ but the responses to FMLP and A23187 were low. NAC-treatment of the smokers resulted in a reduced degree of both PMA- and STZ-induced O(2)-generation in five individuals. In two other subjects, PMA-induced (but not STZ-induced) O(2)-generation was reduced. Two individuals showed increased O(2)-generation to PMA- and to STZ-stimulation after NAC-treatment. Mean values of O(2)-generation induced by A23187 or by FMLP were significantly reduced for cells harvested after NAC-treatment. Mean values for PMA-induced O(2)-generation also tended to be reduced by the treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcysteine↗
PubMed1985

Inhibition of ornithine decarboxylase activity and cell growth by diamines: a comparison between the effects of two homologs, 1,3-diaminopropane and 1,4-diaminobutane (putrescine).

The ornithine decarboxylase (ODC) activity of Ehrlich ascites tumor cells was almost completely inhibited by treatment with either putrescine (10 mM) or 1,3-diaminopropane (5 mM). 1,3-Diaminopropane treatment eradicated the cellular content of putrescine and reduced that of spermidine and spermine. Putrescine treatment caused a dramatic increase in cellular putrescine content and a temporary decrease in spermidine and spermine content. Despite the fact that 1,3-diaminopropane and putrescine inhibited the ODC activity more effectively than did alpha-difluoromethylornithine (DFMO), an enzyme-activated irreversible inhibitor of ODC, they were considerably less antiproliferative in action. However, as compared to DFMO the diamines were less effective in reducing the total polyamine (putrescine + spermidine + spermine) content of the cells.

Animals↗
PubMed1985

Cell cycle phase-dependent induction of ornithine decarboxylase-antizyme.

The activities of ornithine decarboxylase (ODC) and ODC inhibitory protein (ODC-antizyme) were studied in Ehrlich ascites tumor cells, separated according to their position in the cell cycle by centrifugal elutriation. Release and/or synthesis of ODC-antizyme was induced by putrescine treatment. Each mouse received an intraperitoneal injection of 25 mumoles of putrescine at 0, 1, 2, and 3 hr after tumor transplantation. Tumor cells obtained from putrescine-treated and control mice at 4 hr after transplantation were separated into fractions representing all phases of the cell cycle. The cell cycle distribution of the tumor cells in each fraction was determined by flow cytometry. In control tumor cells the ODC activity exhibited two maxima; in late-G1/early-S and in late-S/G2. A marked decrease in ODC activity was observed in mid-S phase. This decrease coincided with maximum ODC-antizyme activity (revealed by putrescine treatment), suggesting that ODC-antizyme is involved in the regulation of ODC activity during the cell cycle.

Animals↗
PubMed1985

Importance of particulate antigen for the induction of dual bronchial reaction in guinea-pigs.

There has been a lack of small animal models for the secondary allergic response (SAR) seen after bronchial challenge in many asthmatic patients. We have found that challenge with particulate instead of soluble antigen will provoke an SAR-like bronchial obstruction in the guinea-pig. The particulate form was obtained by coupling the antigen covalently to Sepharose beads (approximately 100 microns). Different experiments suggest that SAR is obtained only when the challenge is induced via IgE-mediated mechanisms and when the antigen is sufficiently large to provoke frustrated phagocytosis by the invading inflammatory cells. As judged in lungs sections SAR was related to bronchiolitis.

Airway Resistance↗