Biomedical subjects

K Kanaki

Publications and source records attributed to K Kanaki.

5 recordsLinked to original sources

PubMed2002

Left side right ventricular cardiomyopathy.

Arrhythmogenic right ventricular cardiomyopathy or dysplasia, a heart muscle disease of unknown cause, is anatomically characterized by variable replacement of myocardial muscle with adipose or fibroadipose tissue. It is usually considered a selective disorder whereas concomitant left ventricular involvement has been noted in a few cases. Two cases of the disease with evidence of extensive left ventricular involvement at pathologic examination are described. Hearts from two patients who died suddenly showed extensive biventricular infiltration by fibrofatty tissue in the first case and exclusively in the wall of the left ventricle the localization of the fatty and fibrotic lesions. These findings might suggest that the various localizations of the fibroadipose tissue are rather different expressions of the same disease and it is preferable to be termed 'arrhythmogenic cardiomyopathy' as other studies also indicate.

Adult↗

PubMed2000

Functional synapse formation between rat olfactory receptor neurons and olfactory bulb neurons in vitro.

To explore the mechanism of the synapse formation between olfactory receptor neurons and neurons in the olfactory bulb, blocks of olfactory epithelium and slices of olfactory bulb were cocultured by a modified slice culture method. After 4 days in culture, neuron specific fibers from the olfactory epithelium block extending to the olfactory bulb slice were observed. After approximately 20 days in culture, application of forskolin, which induces excitatory responses in olfactory receptor neurons, to the epithelium induced inward current responses in olfactory bulb neurons under the voltage clamp conditions, indicating that functional synapses between olfactory receptor neurons and olfactory bulb neurons had been established in vitro conditions.

Animals↗

PubMed1997

Carnosine-induced inward currents in rat olfactory bulb neurons in cultured slices.

Olfactory neurons are rich in carnosine, which is regarded as a possible neurotransmitter between olfactory neurons and the olfactory bulb neurons. In the present study, we used the organotypic slice culture technique to culture olfactory bulb neurons and explore carnosine's role in the olfactory system. Inward current responses to carnosine upon increases in membrane conductance were recorded under whole-cell voltage-clamp conditions. The inward currents were desensitized during continuous application of carnosine. At carnosine concentrations above 50 microM, the current responses increased with increases in carnosine concentrations. The present results suggest that carnosine serves as an excitable neuroeffector between olfactory neurons and olfactory bulb neurons.

Animals↗

PubMed1996

Ca2+ and Cl(-)-dependence of the turtle olfactory response to odorants and forskolin.

In the turtle olfactory system, large responses to odorants appeared after application of cAMP of forskolin at high concentrations to the isolated olfactory receptor neurons or the olfactory epithelium, suggesting that a cAMP-independent pathway greatly contributes to the generation of odor responses. We measured the effects of the mucosal Ca2+ and Cl- concentrations and a Ca(2+)-activated Cl(-)-channel blocker, 4-acetamide-4'-(isothiocyano) stilbene-2,2'-disulphonic acid (SITS), upon olfactory bulbar responses to explore the contribution of the Ca(2+)-activated Cl(-)-channels to cAMP-dependent and independent pathways. Elimination of mucosal Ca2+ by addition of 2 mM EGTA to the stimulating solution partially inhibited the cAMP-independent responses to 0.1 mM citralva but did not affect those to 0.1 mM lilial or 0.1 mM l-carvone. Substitution of mucosal Cl- with gluconate slightly enhanced the total response to 0.1 mM citralva but practically did not affect the responses to other odorants tested. SITS (2 mM) partially inhibited the responses to 50 microM forskolin and 0.1 mM citralva but did not affect the cAMP-independent response to 0.1 mM citralva in Ca(2+)-free Ringer's solution. These results suggested that the Ca(2+)-activated Cl- channels do not contribute to the generation of the cAMP-independent responses, but that they partially contribute to the generation of the cAMP-dependent responses in the turtle.

4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfo↗

PubMed1996

Difference in behavior between responses to forskolin and general odorants in turtle vomeronasal organ.

To elucidate the signal transduction mechanisms in the turtle vomeronasal receptor neurons, the effects of forskolin, changes in mucosal Ca2+ concentrations and ruthenium red on the responses of the accessory olfactory bulb to general odorants were examined. Forskolin elicited a large response, suggesting that there are cAMP-gated channels in the vomeronasal neurons. On the other hand, the dependence of the responses to general odorants on Ca2+ concentrations was different from that of the response to forskolin. A large response to an odorant (n-amyl acetate) appeared after the cAMP-mediated pathway was fully desensitized by application of 50 microM forskolin. These results suggest that the cAMP-mediated pathway does not contribute significantly to generation of the response to general odorants. A concentration of 50 microM ruthenium red significantly reduced the responses to n-amyl acetate alone and after 50 microM forskolin desensitization, suggesting that the inositol triphosphate-mediated pathway contributes partly to generation of the responses to general odorants in the vomeronasal neurons.

Animals↗