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Biomedical subjects

C Mayer

Publications and source records attributed to C Mayer.

At least 145 records · Page 8Linked to original sources

Interactions between non-symmetric mechanical vector forces in the body and the autonomic nervous system: basic requirements for any mechanical technique to engender long-term improvements in autonomic function as well as in the functional efficiency of the respiratory, cardiovascular, and brain systems.

There are known anatomical asymmetries in the respiratory, cardiovascular, and nervous system. The coupling mechanisms between each of these systems--lungs-heart, heart-brain, and lungs-brain--are also asymmetrical. There is a growing body of literature indicating that mechanical pressure asymmetrically applied to certain areas of the human body produces changes in the balance of autonomic parameters. These findings implicitly indicate that not only magnitude but also the direction and point of application of the force play a role in its influence upon the autonomic nervous system. Therefore, we suggest that asymmetrical vector forces resulting from the mechanical activity of the lungs, heart and blood moving throughout the circulatory system, will also produce a lateralization effect in autonomic balance.

Autonomic Nervous System↗

Interactions between non-symmetric mechanical vector forces in the body and the autonomic nervous system: basic requirements for any mechanical technique to engender long-term improvements in autonomic function as well as in the functional efficiency of the respiratory, cardiovascular, and brain systems.

There are known anatomical asymmetries in the respiratory, cardiovascular, and nervous system. The coupling mechanisms between each of these systems--lungs-heart, heart-brain, and lungs-brain--are also asymmetrical. There is a growing body of literature indicating that mechanical pressure asymmetrically applied to certain areas of the human body produces changes in the balance of autonomic parameters. These findings implicitly indicate that not only magnitude but also the direction and point of application of the force play a role in its influence upon the autonomic nervous system. Therefore, we suggest that asymmetrical vector forces resulting from the mechanical activity of the lungs, heart and blood moving throughout the circulatory system, will also produce a lateralization effect in autonomic balance. We postulate the existence of negative feedback loops between brain autonomic control and mechanical functions in the body as a fundamental part of the body's homeostatic mechanisms. It follows that any mechanical assist to the respiratory or cardiovascular system will be significantly reduced or even eliminated if these homeostatic mechanisms are not taken into account. Our hypothesis predicts that a long-term improvement in autonomic balance as well as in respiratory, cardiovascular, and brain function can be achieved if mechanical forces are applied to the body with the aim of reducing existing imbalances of mechanical force vectors. This technique implies continually controlling for precise timings resulting from physiological periodical forces as well as factors derived from anatomical and coupling asymmetries in the respiratory, cardiovascular, and nervous systems.

Autonomic Nervous System↗

Comparative analytical studies on recombinant and native human somatotropin.

In polyacrylamide gel electrophoresis and isoelectric focusing, somatotropin produced by recombinant DNA technology is as heterogeneous as highly purified native pituitary somatotropin. This heterogeneity is not attributable to different degrees of deamination of a single molecular species. In addition to the main protein of 22 kDa, the cloned products contain traces of interchain disulphide dimers of somatotropin. The quantitative amino acid analyses of the three cloned somatotropins investigated are neither identical nor do they correspond to the analysis of the native pituitary hormone. Moreover, there are discrepancies between the amino acid compositions of the hormones studied and the generally recognized amino acid analysis for human somatotropin.

Amino Acids↗

Different capacities for amino acid transport in periportal and perivenous hepatocytes isolated by digitonin/collagenase perfusion.

Periportal and perivenous hepatocytes were isolated from rat liver by digitonin/collagenase perfusion for investigating the acinar heterogeneity of amino acid transport activities related to glutamine and ammonia metabolism. Immunocytochemical staining of the respective subpopulations for glutamine synthetase demonstrated that periportal subpopulations were essentially free of glutamine synthetase-positive cells, whereas perivenous subpopulations showed a 2- to 3-fold enrichment of glutamine synthetase-positive hepatocytes. The high perivenous/periportal ratio of 59 found for glutamine synthetase activity as well as the perivenous/periportal ratios of other marker enzymes further indicated the good separation of periportal and perivenous cells. alpha-Aminoisobutyric acid, histidine and glutamate were used to determine the distribution pattern of amino acid transport systems A, N and G-, as well as of the sodium-independent uptake of these compounds 1 hr after isolation and after maximal hormonal stimulation during primary culture. The strong heterogeneity of the sodium-independent transport of histidine, characterized by higher perivenous transport rates [perivenous/periportal ratio: 1.5 (1 hr) to 3.5 (48 hr)], suggests a significant role of facilitated diffusion, presumably in glutamine export. Conversely, the strong heterogeneity of the sodium-dependent glutamate transport (System G-) characterized by higher uptake rates in nonstimulated [perivenous/periportal ratio: 6.6 (1 hr)] and in hormonally treated perivenous hepatocytes (perivenous/periportal ratio: 2.2) reflects its possible significance with respect to the substrate availability for glutamine synthesis. The observed heterogeneities provide a basis for understanding how substrate fluxes related to glutamine metabolism might be established and regulated.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗

Mental handicap, psychosis and thyrotoxicosis: a demonstration of the usefulness of an integrated community and hospital service.

A case is described of a moderately mentally handicapped woman referred to the local community mental handicap team with a diagnosis of bipolar affective disorder--manic phase. There was a possible association between her manic state and hyperthyroidism. Assessment and management were complicated by the development of neuroleptic-induced catatonia. The desirability of access to a local general psychiatric unit is discussed.

Antipsychotic Agents↗

Changes in Levels of alpha-Amylase Components in Barley Tissues during Germination and Early Seedling Growth.

Kernels of Klages barley (Hordeum vulgare L.) were germinated for 1 to 4 days on moist sand at 18 degrees C. Representative kernels from each time period were dissected to give the following fractions: scutellum, subscutellar endosperm, aleurone-scutellum interface, remaining aleurone, subaleurone endosperm, and core endosperm. These tissues were analyzed for alpha-amylase components by isoelectric focusing and rocket-line immunoelectrophoresis. Although aleurone and scutellar tissues appeared to synthesize the same alpha-amylase components, enzyme was detected first in the scutellum. A larger proportion of scutellar alpha-amylase was excreted into the endosperm compared to aleurone synthesized alpha-amylase. Aleurone cells appeared to synthesize appreciably more alpha-amylase than did scutellar tissue.

Journal Article↗

Association frequency and silver staining of nucleolus organizing regions in hyperthyroid patients.

The intensity of the silver staining of nucleolus organizing regions (NORs) and the frequency of chromosomal associations were studied before and after antithyroid treatment in seven and eight hyperthyroid patients, respectively. For one patient, the NOR staining was significantly more intense after treatment, while for another the opposite result was found. A higher stainability of chromosome 22 was observed after treatment in six of seven patients. The difference was significant for the group of patients considered as a whole but only for one patient considered separately. Chromosome 22 also showed an increased association frequency. Fro one patient, the number of large associations and the total number of associating chromosomes was also significantly increased after treatment. A decrease of associating chromosomes 14 and 21 such as was reported by Nilsson et al, (1975) after antithyroid treatment could not be found in our sample. The possible reason for this difference are discussed.

Chromosomes, Human↗

Beta-N-acetylhexosaminidase: a target for the design of antifungal agents.

This review provides biochemical, analytical, and biological background information relating to beta-N-acetylhexosaminidase (HexNAc'ase; EC 3.2.1.52) as an emerging target for the design of low-molecular-weight antifungals. The article includes the following: (1) a biochemical description of HexNAc'ase (reaction catalyzed, nomenclature, and mechanism of action) that sets it apart from other, similar enzymes; (2) an overview and a critical evaluation of methods to assay the enzyme, including in crude extracts (photo- and fluorometric procedures with model substrates; HPLC/pulsed amperometric detection of N-acetylglucosamine and chito-oligomers; end-point vs. rate measurements); (3) a summary of some general characteristics of HexNAc'ases from fungi and organisms of other types (Km values, substrate preference, and glycoconjugation); (4) an hypothesis of a specific target function of wall-associated HexNAc'ase (a component of the assembly of surface-located enzymes effecting a continuous turnover and remodelling of the wall fabric through its combined hydrolytic and transglycosylating activities, and a mediator enzyme acting in concert with chitinase and chitin synthase to provide for the controlled lysis and synthesis of chitin during growth); (5) a tabulation of the structural formulae of reaction-based HexNAc'ase inhibitors with Ki values < or = 100 microM (some of them representing transition state mimics that could serve as leads for the development of new antifungals); and (6) an outline of approaches towards the establishment of a three-dimensional model of HexNAc'ase suitable for a truly rational design of antimycotics as well as agricultural fungicides.

Animals↗

Improved preparation and physical studies of polybutylcyanoacrylate nanocapsules.

An improved method for the preparation of alkylcyanoacrylate nanocapsules is proposed that involves the intermediate synthesis of a well defined adduct of a single monomer unit to an ethanol molecule. It leads to thinner capsule walls and, generally, to a more reproducible capsule structure. The chemical composition of the intermediate organic phase has been studied by nuclear magnetic resonance spectroscopy. The morphology and size of resulting structures is analysed, applying analytical ultracentrifugation and light microscopic particle tracking. The sizes of capsules prepared in the described manner depend on the concentrations of the oil and the monomer components, as is shown by the results of a set of experiments following a simple factorial design.

Capsules↗

Cloning, production, characterization and IgE cross-reactivity of different manganese superoxide dismutases in individuals sensitized to Aspergillus fumigatus.

BACKGROUND: Manganese superoxide dismutase (MnSOD) from Aspergillus fumigatus has been demonstrated to be an allergen showing a high degree of homology with phylogenetically distant MnSODs. We describe cloning, production and characterization of MnSODs from different species. METHODS: MnSODs were cloned by PCR, expressed as inclusion body protein in Escherichia coli, purified by Ni2+-chelate affinity chromatography and characterized. RESULTS: The MnSODs from A. fumigatus, man, yeast, Drosophila melanogaster and E. coli show about 50% identity and 70% similarity on the primary structure. All proteins were produced at a high level in E. coli and refolded to achieve enzymatic activity. The proteins were able to bind IgE from sera of individuals sensitized to the A. fumigatus MnSOD. CONCLUSIONS: MnSOD represents a novel pan-allergen restricted to individuals sensitized to A. fumigatus.

Allergens↗

Alternative views.

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Attitude of Health Personnel↗

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Attitude to Health↗

13C nuclear magnetic resonance studies on selectively labeled bacterial biofilms.

Bacterial biofilms of Pseudomonas aeruginosa selectively labeled by introduction of 2-13C-glycerol was studied by solid-state and high-resolution nuclear magnetic resonance. The 13C nuclei were mainly integrated into mannuronate and guluronate, the two monomer units forming the bacterial alginate. The signal for the C5 position of the mannuronate, which was easily identified and well separated from other peaks, was analyzed for molecular mobility. The result indicated a high degree of motional freedom within the molecular network of the alginate. Despite the fact that the alginate was part of a solid aqueous gel phase, the reorientation mechanism of the monomer units came close to isotropic tumbling. Solid-state spectra of biofilms labeled in the described manner may serve as a valuable tool for noninvasive analyses of molecular mobility of the alginate component under various influences, thereby revealing important structural information. In addition, the effect of a monovalent electrolyte (LiCl) on the molecular mobility of alginate fragments in an aqueous solution was studied by determining the spin-lattice relaxation times, line widths and line shapes under variations of the ion concentration. The presence of ions accelerated overall motions but left rapid local motions virtually unaffected.

Biofilms↗