Taisuke Kurokawa

Frontal cortical projections from the suprageniculate nucleus in the rat, as demonstrated with the PHA-L method

Frontal cortical projections from the rat suprageniculate nucleus (SG) were investigated by an anterograde tracing using Phaseolus vulgaris-leucoagglutinin (PHA-L). After PHA-L injection into the SG, labeled terminals were found in the frontal and temporal cortical regions. Labeled terminals in the frontal cortex were almost exclusively localized in the medial agranular area, and those in the temporal cortex were mainly localized in the primary and associational auditory areas. The labeled terminals in cortices were distributed predominantly in layers I, III and IV. The results suggest that ascending information through the SG projects to the medial agranular area in the frontal cortex as well as to the temporal cortex.

Retrograde axonal transport of different fluorescent tracers from the neocortex to the suprageniculate nucleus in the rat

The retrograde fluorescent tracers in a combination of two different dyes (Fluoro gold/Nuclear yellow or Fast blue/Fluoro gold) were used for the study of the projections from the medial geniculate body to the frontal and temporal cortices in rats. There were only single-labeled cells, no double-labeled ones in the medial geniculate body (MGB). The suprageniculate nucleus (SG) was considered to be the origin of the rat direct pathway to the frontal cortex. The present results suggest that projections from the suprageniculate nucleus to the frontal cortex and the temporal cortex consist of separate neuronal groups in the rat MGB and SG. The inputs to the SG from the auditory and oculomotor system may be processed in different ways.

Hematoporphyrin Derivative Concentration in Transplanted Squamous Cell Carcinomas in the Mouse

The distribution of hematoporphyrin derivative (HpD) in mice with transplanted dermal carcinoma was compared with that in normal tissues such as liver, tongue, spleen, kidney and skin on 1, 2, 3, 4, 7 and 9 days after HpD i.p. injection. The samples prepared from each tissue and tumor were used to measure the HpD content by a fluorescence spectrophotometer. HpD concentration in the dermal carcinoma was still higher than that in the normal skin from 4 to 9 days after HpD injection. The dermal carcinoma with necrosis showed higher HpD concentration than that without necrosis. HpD accumulation in tissue is probably due to host factors like vascular formation, vascular permeability, lymphatic clearance, and route of HpD administration.

Chemotherapy in malignant head and neck tumor.

In the multi-disciplinary treatment of head and neck tumors, anti-cancer chemotherapy was evaluated by the survival rate, response rate and preservation of function and shape. Chemotherapy significantly improved the survival rates in cervical esophageal, hypopharyngeal and maxillary cancer and malignant lymphoma in stage II. A new regimen of Pepleomycin, Vincristine, Endoxan, Mitomycin-C, Predonine, 5-Fu and Adriacin showed a better than partial response in 42% of the patients. Functional preservation with combined chemotherapy was observed only in maxillary cancer.Chemosensitivities for head and neck malignant tumors were measured in order to select useful drugs. Although no concrete merit of these tests has yet been achieved, inoperable recurrent carcinoma or maxillary cancer will be treated by more selective anti-cancer drugs. Furthermore, photoradiation therapy with hematoporphyrin derivatives will become a useful modality for head and neck tumors in the near future, because this technique does not destroy normal tissue.

Mass Examination for Early Detection of Glottic Cancer

Mass examination of laryngeal cancer has been attempted only in a few area in this country. From May to July in 1984, our mass examination for early detection of glottic cancer and other diseases of the vocal fold was performed in co-operation with eight health centers, twenty four E. N. T. clinics and a local press in Fukui prefecture.Six hundred and eleven patients, who complained of hoarseness, underwent the examination. They consisted of 343 males and 268 females. Age distribution of the patients was 68 in thirties, 211 in fourties, 260 in fifties, 75 in sixties, 50 in seventies, 6 in eighties and 1 in nineties.Seven males (1.2%) of the glottic cancer and eight males of precancer (seven hyperkeratosis and one leukoplakia) were found among the 611 patients. In these laryngeal cancers, six cases were T1a of early stage and one was T3 in the classification by Intenational Union Against Cancer (UICC).Other 596 patients distributed to 296 chronic laryngitis, 60 acute laryngitis, 66 laryngeal polyp, 41 Rienkes edema, 55 laryngeal nodule and others.We achieved our purpose by early detection of six glottic cancers in this mass examination, and look foward to the examination same as ours in other prefectures.