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Biomedical subjects

M Kopp

Publications and source records attributed to M Kopp.

At least 55 records · Page 3Linked to original sources

Possible role of sweating in the pathophysiology of panic attacks.

In recent years the role of hyperventilation in the generation of panic attacks has attracted a considerable amount of interest. According to these studies hyperventilation can elicit the somatic symptoms of panic due to systemic alkalosis. We suggest that since in the case of panic, sweating might cause alkalosis, it could also contribute to the generation of panic attacks. In light of this hypothesis we made a statistical analysis of the panic symptoms of 111 panic patients diagnosed according to DSM-III criteria. The analysis revealed that: (1) there was a well identified group of panic patients who had minor breathing difficulties with heavy sweating; and (2) that all the patients sampled had either severe breathing, or sweating symptoms, or both. We conclude that in the absence of the intensive physical activity of the 'flight or fight' reaction, sweating as well as hyperventilation can cause alkalosis, which in turn might generate panic attacks.

Alkalosis, Respiratory↗

Why do young women use sunbeds? A comparative psychological study.

Many people are keen on getting a skin tan despite being aware of warnings of health hazards. The present study investigates differences between women regularly using sunbeds and a control group of non-users in the areas of self-concept, narcissistic regulatory modalities, social assertiveness and generalized self-efficacy. Thirty women users of suntan salons and 34 women who never used one were investigated with standardized psychological questionnaires. In addition, their knowledge about the hazards of using sunbeds and attitudes to tanning were recorded. Statistical evaluation shows that sunbed users demonstrate more object devaluation: that is, other persons are devalued so that they are not even considered worthy of affection. Furthermore, they also display greater anxiety in their feelings and relationships with others. The results of this pilot study support the hypothesis that a tanned skin, by helping sunbed users to achieve their ideal of beauty, enables them to devalue other people and thus possibly to protect themselves from close relationships. As medical information about the hazards of ultraviolet irradiation fails to make an adequate impression on them, public relations campaigns must be undertaken in order to make them aware of the underlying motives of their behaviour.

Adult↗

[Psychiatric problems in bone marrow transplantation patients during isolation].

Psychological stress is extremely high in patients with oncological diseases. About 50% of all cancer patients show psychological signs and symptoms which are related to the multiple stress factors of their oncological illness. Although many psychological problems connected with cancer are well known, additional acute stress could result from new therapeutic strategies which require settings similar to intensive care, e.g. bone marrow transplantation. For 2 years the Department of Psychiatry in Innsbruck has provided a "liaison service" at the Department of Bone Marrow Transplantation. Within this observation period, 40 patients have received psychooncological care. The diagnostic distribution according to DSM III-R and specific psychooncological interventions are presented.

Adult↗

Expression and function of the trehalase genes NTH1 and YBR0106 in Saccharomyces cerevisiae.

The biological function of the trehalose-degrading yeast enzyme neutral trehalase consists of the control of the concentration of trehalose, which is assumed to play a role in thermotolerance, in germination of spores, and in other life functions of yeast. Resequencing of the neutral trehalase gene NTH1 on chromosome IV resulted in the observation of two possible start codons (Kopp, M., Nwaka, S., and Holzer, H. (1994) Gene (Amst.) 150, 403-404). We show here that only the most upstream start codon which initiates translation of the longest possible ORF is used for expression of NTH1 in vivo. A gene with 77% identity with NTH1, YBR0106, which was discovered during sequencing of chromosome II (Wolfe, K. H., and Lohan, A. J. E. (1994) Yeast 10, S41-S46), is shown here to be expressed into mRNA. Experiments with a mutant disrupted in the YBR0106 ORF showed, in contrast to a NTH1 deletion mutant, no changes in trehalase activity and in trehalose concentration. However, similar to the NTH1 gene a requirement of the intact YBR0106 gene for thermotolerance is demonstrated in experiments with the respective mutants. This indicates that the products of the likely duplicated YBR0106 gene and the NTH1 gene serve a heat shock protein function. In case of the YBR0106 gene, this is the only phenotypic feature found at present.

Adaptation, Physiological↗

Structural features of fungal beta-D-glucans for the efficient inhibition of the initiation of virus infection on Nicotiana tabacum.

Glucans of fungal origin have been shown to inhibit the early stages of infection of Nicotiana by numerous viruses of different taxonomic groups. Several glucans were isolated from the cell walls of Phytophthora parasitica, Phytophthora megasperma f. sp. glycinea (Pmg) and Fusarium oxysporum, and their antiviral activity compared on tobacco leaves inoculated with tobacco mosaic virus. These polysaccharides consist of a mixture of (1-->3)(1-->6)-beta-D-glucans with M(r) varying from 1.1 x 10(3) to 2 x 10(6). Requirements for a prominent antiviral activity of the fungal polysaccharides are a beta-(1-->3)(1-->6)-D-glucan structure with mono-, di-, tri- or tetra-glucosidic side branches attached to a linear main chain of beta-(1-->3)-linked-D-glucose residues. Very high activity is correlated with a high degree of branching at position 6 and with the size and glycosidic nature of the side chains. The molecular masses and the organized structure of fungal beta-D-glucans are not essential for their antiviral activity. The structural motif for antiviral activity in Nicotiana is distinct from that required for elicitation of phytoalexins in soybean cotyledons.

Antiviral Agents↗

Tobacco smoking in young adults from 21 European countries: association with attitudes and risk awareness.

Information concerning tobacco smoking was obtained in a survey of 16,483 students aged 18-30 years from 21 European countries. Belief in the benefits to health of not smoking were also assessed. Risk awareness was measured in terms of knowledge of the links between smoking and disease. The overall age-adjusted prevalence of smoking was 33.1% in men and 29.0% in women, but wide variations were observed across country samples. Significant sex differences were found in only a minority of cases. The inclusion of respondents who stated that they had sometimes smoked in the past substantially reduced variations in prevalence across country samples. Beliefs in the health benefits of not smoking were consistently associated with smoking behaviour. Awareness of the link between smoking and lung cancer was uniformly high, but awareness of the role of smoking in heart disease varied considerably across country samples, and averaged only 64.4% in men and 62.9% in women. In the majority of countries, risk awareness was greater among smokers than non-smokers. The results suggest that in this selected sector of the population of young adults in Europe, sex differences in smoking are relatively minor, robust associations between attitudes and smoking behaviour can be identified, and there are major gaps in risk awareness.

Adolescent↗

A new elicitor of the hypersensitive response in tobacco: a fungal glycoprotein elicits cell death, expression of defence genes, production of salicylic acid, and induction of systemic acquired resistance.

A 32 kDa glycoprotein whose effects in tobacco and other Nicotianae mimic a typical hypersensitive response, was isolated from Phytophthora megasperma. Infiltration of a few nanograms of the protein into leaves caused the formation of lesions that closely resemble hypersensitive response lesions. Transcripts of genes encoding enzymes of the phenylpropanoid and sesquiterpenoid pathways accumulated rapidly after elicitor application followed by salicylic acid production. Cellular damage, restricted to the infiltrated zone, occurred only several hours later, at a time when expression of PR protein genes was activated. After several days systemic acquired resistance was also induced. Thus, tobacco plant cells that perceived the glycoprotein generated a cascade of signals acting at local, short, and long distances, and causing the coordinate expression of specific defence responses in a way similar to hypersensitivity to tobacco mosaic virus. The glycoprotein represents a powerful tool to investigate further the signals and their transduction pathways involved in induced disease resistance. It may also be useful to engineer broad disease protection in a Nicotianae and possibly into crop plant species.

Cell Death↗

Is thermotolerance of yeast dependent on trehalose accumulation?

During heat stress, trehalose concentration increases in yeast cells in parallel to thermotolerance. This parallelism suggested that trehalose mediated thermotolerance. We show in this work that, under certain conditions, trehalose accumulation and increase in thermotolerance do not go in parallel. A mutant deficient in the trehalose-degrading neutral trehalase shows, after shift from 40 degrees C to 30 degrees C, low thermotolerance in spite of a high trehalose concentration. When glucose is added to stationary yeast cells with high trehalose concentration and high thermotolerance, trehalose concentration decreases while thermotolerance remains high. A mutant deficient in ubiquitin-conjugating genes, ubc4ubc5, shows during exponential growth a low trehalose concentration, but a high thermotolerance, in contrast to wild-type cells. Because the ubc4ubc5 mutant synthesizes heat-shock proteins constitutively, it is proposed that, under these conditions, accumulation of heat-shock proteins, and not trehalose [corrected], mediates thermotolerance.

Gene Deletion↗

[Differential stress management pattern of seropositive and seronegative polyarthritis patients. A brief comment on the publication, "Polyarthritis patients with and without detected rheumatoid factor: a psychological personality comparison"].

46 seropositive female RA patients were compared to 28 seronegative female RA patients using the Stress Coping Questionnaire of Janke et al. (1985). In comparison to seropositive patients, seronegative patients exhibit a stress coping behaviour characterized by more self-pity but less substitutive gratification. They too show fewer attempts at controlling their reactions.

Adaptation, Psychological↗

Molecular analysis of the neutral trehalase gene from Saccharomyces cerevisiae.

Neutral trehalase (EC 3.2.1.28) is a trehalose hydrolyzing enzyme of the yeast Saccharomyces cerevisiae (App, H., and Holzer, H. (1989) J. Biol. Chem. 264, 17583-17588). The gene of neutral trehalase was cloned by complementation of a neutral trehalase-deficient yeast mutant which was obtained by ethylmethanesulfonate mutagenesis. Three mutants without detectable neutral trehalase activity were obtained and characterized by tetrad analysis and found to belong to the same complementation group. The mutants were transformed with a S. cerevisiae genomic library in YEp24. Two overlapping plasmids were isolated, containing the neutral trehalase gene NTH1 with an open reading frame of 2079 base pairs (bp), encoding a protein of 693 amino acids, corresponding to a molecular mass of 79,569 Da. Several putative TATA boxes were found in the 5'-nontranslated region of the NTH1 gene. In positions -652 to -641 a possible binding sequence for the MIG1 protein, a multicopy inhibitor of the GAL1 promotor, which also binds to the promotor sequences of the SUC2 and the FBP1 gene, was found. The start codon of the neutral trehalase is located about 2500 bp upstream of the centromere 4 consensus sequence elements I, II, and III (Mann, C., and Davis, R. W. (1986) Mol. Cell. Biol. 6, 241-245). Vicinity to a centromere is known to have a depressing influence on the number of plasmid copies per cell. This probably explains why transformation with pNTH does not lead to overexpression of neutral trehalase. The four consensus sequences AATAAA contained in the centromeric elements and reconfirmed by our sequencing data might be polyadenylation signals for NTH1-mRNA transcription termination. Northern blot analysis yielded a single mRNA species of approximately 2.3 kilobase(s). The neutral trehalase protein has a putative cAMP-dependent phosphorylation consensus sequence RRGS from amino acid positions 22-25. Therefore, the previously described activation of neutral trehalase by cAMP-dependent phosphorylation is probably due to phosphorylation of serine 25. Three potential N-glycosylation sites (Asn-X-Ser/Thr) occur in the open reading frame of the neutral trehalase gene. However, no evidence for glycosylation could be detected by Western blotting.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acid Sequence↗

Carbonic anhydrase activity in the peripheral nervous system of rat: the enzyme as a marker for muscle afferents.

The distribution of carbonic anhydrase (CA) activity was determined histochemically using Hansson's cobalt phosphate method in cross-sections of peripheral nerves from rats. As the studied nerves contain either efferent, proprioceptive or exteroceptive myelinated fibres, our survey particularly focused on the question whether CA-reactive nerve fibres are functionally related. Intense CA activity was detected in all large diameter (8-12 microns) muscle afferents. The amount of similarly reactive cutaneous afferents was negligibly low (3.6%). Efferent fibres displayed only weak CA activity, which was confined to the small myelinated fibres (3-6 microns). Moderate staining could be assessed in medium-sized (4-11 microns) proprioceptive fibres. The same reactivity occurred in a sizeable percentage (11.4%) of exteroceptive afferents. Their diameters ranged from 4 to 11 microns. These results indicated, that high enzyme activity is found predominantly in large-calibre proprioceptive afferents, which according to Hunt's classification were identified as group IA and IB fibres. Further confirmation for our observations was obtained by demonstrating high levels of enzyme activity in primary nerve endings of muscle spindles (IA fibres) and in axon terminals of Golgi tendon organs (IB fibres) constantly. Finally possible functions for neuronal CA are discussed with respect to its high activity in a functionally related subpopulation of nerve fibres.

Animals↗

What does the legacy of Hans Selye and Franz Alexander mean today? (The psychophysiological approach in medical practice).

At the founding session of the Working Group of Psychophysiology, Hungarian Psychiatric Society, the authors summarized the psychophysiological legacy of two Hungarian-born researchers, Hans Selye and Franz Alexander in medicine today. Emotional dysfunctions, anxiety and depression are a substantial risk factor in the emergence, course and recurrence of many illnesses of great epidemiological significance, such as ischemic heart diseases, in the prognosis of hormone-sensitive tumours in the middle-aged and, obviously, in alcoholism and suicide. In modern society the reduction of creative ability and the capacity for work is caused primarily not by physical damage, but rather by states of depression with anxiety and functional disorders arising as a result of transitional or lasting failure of the psychological capacities to resolve conflicts, leading to such states as chronic pain syndrome, functional cardiovascular and gastroenterological disorders. According to prognoses based on the above, lasting results can only be expected of preventive health programs if they take the results of modern psychophysiology seriously into account. On the basis of the recent theoretical achievements, we are capable not only of treating the symptoms but also of intervening in the causes. Psychotherapeutic methods and psychopharmacology supplement each other within this theoretical framework.

Adult↗

Electrodermally differentiated subgroups of anxiety patients and controls. II: Relationships with auditory, somatosensory and pain thresholds, agoraphobic fear, depression and cerebral laterality.

Patients diagnosed (DSM III) with anxiety disorders (agoraphobia, panic syndrome, generalised anxiety syndrome) were classified along with controls as electrodermally stabile or labile on the basis of non-specific electrodermal activity and rate of habituation to tones. While patients showed more evidence of psychopathology than controls on scales of anxiety, neuroticism, depression and agoraphobic fear, patient labiles scored higher than stabiles on agoraphobic fear and were differentiated by higher scores of Beck depression. They were also more sensitive to pain, whereas patient stabiles were less sensitive at absolute somatosensory threshold. Amongst controls agoraphobic fear was associated with lability and stabiles scored higher on autonomy in locus of control. Lateral asymmetries in auditory thresholds were consistent with reciprocal hemispheric influences on electrodermal reactivity and habituation, modifiable by anxiety. Interrelationships between fear, depression, sensitivity to somatosensory stimulation, pain, and superior vigilance performance in patient labiles were consistent with elevated right hemisphere function.

Agoraphobia↗

Host-Pathogen Interactions : XXXII. A Fungal Glucan Preparation Protects Nicotianae against Infection by Viruses.

A glucan preparation obtained from the mycelial walls of the fungus Phytophthora megasperma f.sp. glycinea and known as an elicitor of phytoalexins in soybean was shown to be a very efficient inducer of resistance against viruses in tobacco. The glucan preparation protected against mechanically transmitted viral infections on the upper and lower leaf surfaces. Whether the glucan preparation was applied by injection, inoculation, or spraying, it protected the plants if applied before, at the same time as, or not later than 8 hours after virus inoculation. At concentrations ranging from 0.1 to 10 micrograms per milliliter, the glucan preparation induced protection ranging from 50 to 100% against both symptom production (necrotic local lesions, necrotic rings, or systemic mosaic) and virus accumulation in all Nicotiana-virus combinations examined. However, no significant protection against some of the same viruses was observed in bean or turnip. The host plants successfully protected included N. tabacum (9 different cultivars), N. sylvestris, N. glutinosa, and N. clevelandii. The viruses belonged to several taxonomic groups including tobacco mosaic virus, alfalfa mosaic virus, and tomato black ring virus. The glucan preparation did not act directly on the virus and did not interfere with virus disassembly; rather, it appeared to induce changes in the host plant that prevented infections from being initiated or recently established infections from enlarging. The induced resistance does not depend on induction of pathogenesis-related proteins, the phenylpropanoid pathway, lignin-like substances, or callose-like materials. We believe the induced resistance results from a mechanism that has yet to be described.

Journal Article↗

Influence of parenteral fat administration on the pulmonary vascular system in man.

In 16 patients with multiple injuries the effect of parenteral administration of a fat emulsion on the pulmonary vascular system has been studied. Using the Hewlett Packard 5600 A Intensive Care System, which allows vital parameters to be sampled at a rate of two values per min, pulmonary artery pressure (PAP) was monitored before, during, and after the administration of Lipofundin S 20% (0.24 g/kg/h). In addition right ventricular stroke work index (RVSWI), alveolar-arterial oxygen difference (A-aDO2) and pulmonary shunt (Qs/Qt) were calculated. The results indicate that there are no changes of the PAP, the RVSWI, and the A-aDO2 during the period of observation.

Adult↗