Search PubMed⌕ Search

Biomedical subjects

T Nagano

Publications and source records attributed to T Nagano.

At least 361 records · Page 20Linked to original sources
PubMed1983

Role of thoracotomy in pulmonary metastases from gestational choriocarcinoma.

Choriocarcinoma responds well to chemotherapy, and its growth can be monitored by measuring human chorionic gonadotropin (HCG) as a tumor marker. Thoracotomy was carried out in six patients with the disease because their pulmonary nodules persisted after repeated courses of chemotherapy over a 4 month period. They were followed up for a long period. These observations suggest that the most important role of thoracotomy is for diagnostic purposes; it is used for therapeutic purposes only when the pulmonary lesion is the only remaining source of increased HCG excretion. Much attention must be paid to tertiary hematogeneous metastases caused by resection of pulmonary foci that are unresponsive to chemotherapy.

Adult↗
PubMed1982

Further observations on the Sertoli cell junctions of the mouse testis after metal contract freeze-fracture, and comparisons with cellular junctions of other epithelial cells.

Using a metal contact freezing methods, the junctional complexes of Sertoli cells and other epithelial cells (intestine, liver, and epididymis) in the mouse were studied by freeze-fracture in unfixed and in aldehyde-fixed specimens. The tight junctions of the Sertoli cells without fixation consists of discrete rows of particles located preferentially on the E face. Continuous furrows with or without tight-junctional particles are found on both fractured faces. The majority of the tight-junctional particles of th Sertoli cells are situated at one side of the furrow rather than in the center. The "aisle" configuration of the gap junction is seen in developing Sertoli cells prepared without fixation. Tight junctions of epithelial cells other than Sertoli cells consists of discrete rows of particles on the E face and furrows on the P face when prepared without fixation. The tight and gap junctions of the Sertoli cells are not affected by fixation, but the tight junctions of other types of epithelial cells are effected as previously suggested. A distribution pattern of the gap-junctional particles of the Sertoli cells and of other cells shows a pleomorphism. Changes in gap junctions produced by fixation could not be detected clearly. Characteristics of the Sertoli-cell junctions are discussed. Desmosomes between the intestinal epithelial cells without fixation are presented.

Animals↗
PubMed1981

A self-organizing neural network model for the development of complex cells.

On the basis of recent neurophysiological findings on the mammalian visual cortex, a self-organizing neural network model is proposed for the understanding of the development of complex cells. The model is composed of two kinds of connections from LGN cells to a complex cell. One is direct excitatory connections and the other is indirect inhibitory connections via simple cells. Inhibitory synapses between simple cells and complex cells are assumed to be modifiable. The model was simulated on a computer to confirm its behavior.

Animals↗
PubMed1980

A model of the complex cell based on recent neurophysiological findings.

A neural network model is proposed for the understanding of the receptive field properties of the complex cell. The model is based on recent neurophysiological findings on the visual cortical network. The model is proved to be functionally identical with Hubel's and Wiesel's hierarchy model though the two models are structurally quite different.

Geniculate Bodies↗
PubMed1980

Temporal sensitivity of the human visual system to sinusoidal gratings.

Temporal sensitivity, defined as the reciprocal of the minimum exposure duration required for a grating to be detected, was measured for gratings with constant contrasts in a range of spatial frequencies. Temporal sensitivity functions were found to be given by curves with maximum sensitivity at 0.7 approximately 0.8 C/deg. Two criteria of detection were used: the detection of any change on the screen and the detection of patterns. The difference between temporal sensitivities under the two criteria was large at low spatial frequencies but was small at high spatial frequencies.

Adult↗
PubMed1980

Belt-like gap junctions in the ductuli efferentes of some mammalian testes.

Cellular junctions of the lining epithelium of the efferent ductules of the mouse, guinea pig, and human testes were examined by freeze-fracture. A belt-like gap juncion consists of a large aggregation of particles with a few fragments of the tight junctional strands and circumferentially occupies the adluminal area between the nonciliated cells. This type of gap junction appears to be one of the components of the junctional complexes in mammalian efferent ductules. Functional significance of the belt-like gap junction is discussed in the light of the findings.

Aged↗