Biomedical subjects

G Hanke

Publications and source records attributed to G Hanke.

10 recordsLinked to original sources

PubMed2004

[Significance of voice constitution as a predisposition for occupational voice disorders].

Occupational voice disorders have been increasing for years. The aim of this study was to examine whether a constitutionally weak voice should be regarded as a risk factor for developing such voice disorders. In a prospective study, 15 female teacher students with a normal vocal constitution were compared with 18 students with constitutionally weak voices during teaching practice. There was a significant difference in the mean fundamental frequency of both groups after teaching for 30 min. Students with constitutionally weak voices tended to have increased values. Taking into consideration the physiological aspects of an increasing fundamental frequency as a sign of vocal fatigue, a constitutionally weak voice has to be regarded as a potential risk factor for developing a voice disorder in vocally intensive occupations. To prevent future vocal problems by appropriate prophylactic intervention (i.e. voice therapy, introduction to vocal hygiene), a phoniatric examination of vocal constitution and endurance is recommended at the beginning of a voice dependent professional career.

Adolescent↗

PubMed2002

[Recording and control of culture parameters in perfused cell culture systems].

For the cultivation of animal cells perfused cell culture systems are advantageous. The measurement of the process parameters for the check of the culture is difficult through the small volumes and dimensions. A developed measuring system allows the measuring of the parameters temperature, pH-value and dissolved oxygen.

Animals↗

PubMed2002

[Realization of a measurement module for determining pH value in perfusion cultures].

For cultivating animal cells in bioreactors the maintenance of a fixed pH-value is of elementary importance. In a perfused cell culture system the pH-value is measured by electrochemical flow rate sensors. For the acceptance of a technical solution the integration in complex workplaces is necessary, thereby small size and low costs are the main features. For that a special measurement module was developed, consisting of measuring amplifier and microcontroller component with CAN-Bus-interface.

Acid-Base Equilibrium↗

PubMed2002

[Development of a CAN (controller area network) bus for modules of a perfused cell culture system].

For computer-aided data acquisition and automated running of experiments in cell cultivation reactors networking of all sensoric and actoric devices is required. A low cost and high performance solution to this demand can be found by using the widely established CAN (Controller Area Network) bus. If standard PCs running MS Windows are used to control this network special measures have to be taken to prevent loss of data caused by differences in the computing power of the PC on one hand and microcontroller-based devices on the other.

Cells, Cultured↗

PubMed1997

CD28-mediated induction of proliferation in resting T cells in vitro and in vivo without engagement of the T cell receptor: evidence for functionally distinct forms of CD28.

JJ316 and JJ319 are rat CD28-specific monoclonal antibodies (mAb) of the gamma1 kappa isotype with identical co-stimulatory potency. At a concentration 100-1000-fold higher than that required for co-stimulation, JJ316, but not JJ319 induces massive proliferation of all T cell subsets in vitro without T cell receptor (TCR) triggering. "Direct" stimulation by JJ316 is fully blocked by JJ319, indicating that it is not due to cross-reactivity of JJ316 with the TCR complex or other activating receptors. JJ316 binds much more slowly to primary T cells than JJ319, whereas both antibodies bind with similar kinetics to CD28-transfected L-929 cells, suggesting that JJ316 binding to T cells requires redistribution or a conformational change of CD28. In vivo, JJ316 but not JJ319 induces rapid and transient proliferation of most CD4 T cells and, indirectly, of B cells. These data show that TCR engagement is not an absolute prerequisite either in vitro or in vivo for the induction of T cell proliferation through CD28 and suggest that mAb JJ316 is able to stimulate resting T cells directly by recruiting CD28 molecules from an inactive to an active form.

Animals↗

PubMed1988