Search PubMed⌕ Search

Biomedical subjects

K Otani

Publications and source records attributed to K Otani.

At least 253 records · Page 14Linked to original sources
PubMed1985

Quantitative morphological changes in the superior colliculus and the parabigeminal nucleus in the bilaterally microphthalmic rat.

Quantitative morphological changes in the superior colliculus (SC) and the parabigeminal nucleus (PB) were studied in hereditary bilaterally microphthalmic rat, which lacks the optic nerve completely. Volumes of the retinorecipient superficial collicular layers of SC (SCS) to the central gray matter were decreased by 35% with respect to the normal. However, the cell density in SCS was increased as much as 150% of the normal. The stratum griseum superficiale was packed densely and irregularly with small-sized round nerve cells. The stratum opticum of the mutant rat appeared as a narrow band with few fiber components, but it contained some medium-sized polygonal neurons. No significant changes were found in the deeper layers of the microphthalmic SC. Bilaterally microphthalmic PB reduced both its volume and cellular density per unit area (about 30 and 75% of the normal, respectively). Furthermore, in contrast to the normal rat, the mutant PB could not be subdivided into the dorsal, middle and ventral subgroups.

Animals↗
PubMed1985

Ascending projections to the lateral thalamic nuclei from the substantia grisea centralis in the rat: a retrograde WGA-HRP study.

Ascending projections to the lateral thalamic nuclear group from the substantia grisea centralis (SGC) were studied by injections of wheat germ agglutinin-conjugated with HRP (WGA-HRP) into the laterodorsal (LD) and lateroposterior (LP) thalamic nuclei. The present study demonstrated that the pars ventralis of the SGC at the levels of the intercollicular region and of the locus ceruleus sent fibers to both the LD and LP on both sides with homolateral predominance. Distribution pattern and morphological characteristics of the LD-projection neurons in the SGC were similar to those of SGC-LP projection cells. WGA-HRP injections into the LD or LP labeled also a considerable number of neurons in the dorsal raphe nucleus and the dorsal tegmental nucleus bilaterally with homolateral predominance, but the nucleus of Darkschewitsch contained labeled neurons only after the LD injection.

Animals↗
PubMed1985

The reciprocal connections of the suprageniculate nucleus and the superior colliculus in the rat.

Reciprocally bilateral connections between the superior colliculus and the suprageniculate nucleus have been studied in the rat, using the anterograde and retrograde transport techniques of HRP. In those cases where the HRP deposit was restricted to the superficial layers of the colliculus, anterogradely labeled fibers and retrogradely labeled neurons were observed in the ipsilateral suprageniculate nucleus. However, upon HRP injection extended into the intermediate layers of the colliculus, the number of labeled fibers and neurons was not only increased ipsilaterally but were also observed in the contralateral suprageniculate nucleus. The density of the labeled fibers and the number of labeled neurons was always greater in the ipsilateral side. These results show that the suprageniculate nucleus and the superior colliculus are connected reciprocally and bilaterally, with an ipsilateral dominance.

Animals↗
PubMed1985

Neuropathological and Golgi study on a case of thanatophotoric dysplasia.

Neuropathological examination of a 3-day-old female with thanatophoric dysplasia revealed abnormal sulci with polymicrogyria and neuronal heterotopia in the temporal lobes and cerebellar hypoplasia. Rapid Golgi stainings showed immature or maldeveloped neurons with short dendrites and a reduced number of spines in the cerebral cortex, and abnormal neurons with peculiar dendrites in the subcortical heterotopia. These abnormalities were predominant at the base of the large brain which occupied the hypoplastic middle and posterior cranial fossas.

Brain↗
PubMed1985

Risk factors for the increased seizure frequency during pregnancy and puerperium.

Possible factors affecting the seizure frequency during pregnancy and puerperium were prospectively studied on 125 cases, paying particular attention to the drug compliance and the antiepileptic drug disposition. Of the subjects, 27% were under the poor compliance category. As the reasons for the poor compliance, anxiety about the side effects of antiepileptic drugs including teratogenecity and the harmful effects on their newborns by breast feeding were found in about half of them. In the cases with regular drug taking, 80% showed no change in the seizure frequency whereas only 16% exhibited an increase and 4% a decrease. The apparent serum clearance of phenytoin, primidone, phenobarbitone derived from primidone and valproic acid increased during pregnancy and puerperium. In some cases, the lowering of the serum level of drugs was associated with the aggravation of seizures.

Anticonvulsants↗
PubMed1985

[Clinical observation of non-gonococcal urethritis].

Sixty-one male urethritis cases, 28 gonococcal urethritis and 33 nongonococcal urethritis (NGU), were out-patients at the Department of Urology, Asahi General Hospital, during the 4 months, Oct. 1, 1984-Jan. 31, 1985. Thirteen of the 33 NGU patients (39.4%) were infected with C. trachomatis (CT). The efficacy of Doxycycline and the route of infection was studied in the cases of CT-positive CT-negative-NGU. CT infection from prostitutes was not so frequent as in the other pathogen infection of NGU. The efficacy of Doxycycline (100 mg b.i.d. for 2 weeks) against CT infection was excellent in the disappearance of subjective complaints and that of white blood cells in the urethral discharge in the CT positive-NGU group (13/13), in comparison with CT negative-NGU group (7/18). The efficacy of Doxycycline against CT was also confirmed from the follow-up study by the isolation of CT and by detection of CT antigen from urethral swabs using FITC conjugated monoclonal antibody against CT antigen.

Chlamydia Infections↗
PubMed1984

The surgical reconstruction of fractures and fracture dislocations of the thoraco-lumbar spine.

Sixty patients have undergone surgical reconstruction of the injured thoraco-lumbar spine during the period 1968 to 1978 at the Spinal Unit of the National Murayama Hospital. The aim of treatment of any fracture, dislocation, or fracture-dislocation of the spine is to render it stable and painfree. This is best achieved by reduction and stabilisation of the involved segment of the spinal column. Where the posterior ligaments and intervertebral disc are ruptured healing of these structures with return to normal stability cannot be anticipated. In order to obtain permanent stability at the affected vertebral level we elect to perform anterior intervertebral fusion.

Adult↗
PubMed1984

Quantitative analysis of the striate cortex in the mutant microphthalmic rat.

A quantitative analysis of the striate cortex of the mutant microphthalmic rat was conducted to determine whether or not transneuronal changes of the visual cortex were induced following the loss of eyes. The area of the striate cortex in the microphthalmic rat was approximately 60% of that in the normal rat. As for the thickness of each layer of the striate cortex, many layers of microphthalmia tended to be thin in comparison with the normal animal, except for layers I and III: the thickness of layers II, IV, V, and VI was about 74, 62, 82, and 82% of normal values, respectively. There was fractically no difference between the number of neurons of each layer of the microphthalmic and the normal striate cortex per unit (10(4) microns2), except for layer IV, in which the density had increased to 117% of the normal value. In many layers, the neurons of the microphthalmic striate cortex were smaller than normal and they had narrow neuroplasmic space. Our study demonstrated that the striate cortex of the microphthalmic rat underwent quantitative and morphometric transneuronal changes. Especially striking changes of the striate cortex were found in the inner granular layer with a reduction in thickness and a diminution of cell size.

Animals↗
PubMed1984

Auditory and non-auditory subcortical afferents to the inferior colliculus in the rat.

Afferent projections to the rat inferior colliculus (IC) were studied by using the method of retrograde transport of horseradish peroxidase (HRP). Microinjection of HRP revealed an ordery arrangement of fiber projections between the cochlear and the central nucleus of IC; it entails a reversal of the dorso-ventral nucleotopic organization. An indistinct dorso-lateral nucleotopic projection was found between the lateral superior olivary nucleus and the central nucleus. Small number of neurons in some brainstem non-auditory structures were always labeled: the parabrachial region of the midbrain lateral tegmentum, the pars lateralis of substantia nigra, dorsal part of the central gray matter at a caudal 2/3 level of IC, and deep layers of the superior colliculus, ipsilaterally, and the spinal trigeminal and posterior column nuclei, contralaterally. Small injection restricted within the external and pericentral nuclei (cortical zone) of IC resulted in a higher distribution ratio of labeled neurons in the non-auditory structures as compared with those in the central nucleus. On the other hand, the ratio in the brainstem auditory nuclei decreased definitely after HRP-injection within the cortical zone, with an exception of the ipsilateral central nucleus of IC which contained many labeled cells following the injections in the cortical zone. The present results suggest a dual function of the inferior colliculus. The central nucleus acts as a relay station in the main auditory system, while the cortical zone, with its converging auditory, visual and somatic inputs, may act as a subcortical integration center for acoustico-motor behavior.

Afferent Pathways↗
PubMed1983

Laminar origin of the tecto-thalamic projections in the albino rat.

Cells of origin of the tecto-LP (lateroposterior nucleus of the thalamus) projection and the tecto-LGNd (dorsal nucleus of the lateral geniculate body) projection were studied in the albino rat by means of retrograde transport of wheat germ agglutinin conjugated to horseradish peroxidase (WGA-HRP). Tecto-LGNd neurons with small spindle form were located in the stratum griseum superficiale of the superior colliculus (SC), whereas tecto-LP neurons with polygonal shape were found in the stratum opticum of the SC.

Animals↗
PubMed1983

Quantitative analysis of the lateral geniculate nucleus in the mutant microphthalmic rat.

A quantitative analysis of the lateral geniculate nucleus was carried out in the mutant microphthalmic rat. In the dorsal lateral geniculate nucleus (LGNd) of the microphthalmic rat we found the total volume and neuronal population were reduced by 45 and 68% of normal values, respectively. The size of normal LGNd neurons was 8 to 20 microns and that of mutant LGNd cells from 6 to 16 microns. Neurons of the normal LGNd were medium-size and round or oval, and their cell bodies were filled with Nissl substance. Microphthalmic LGNd neurons, on the other hand, had narrow cytoplasmic spaces with few Nissl granules, and pale cell nuclei. In the microphthalmic rat, the lateral part of the ventral lateral geniculate nucleus (LGNvl) also showed a marked reduction in the total volume and neuronal population which were 42 and 76% of normal values, respectively. The size of normal LGNvl neurons was 8 to 20 microns and that of the microphthalmic neurons from 6 to 16 microns. These findings suggested that a marked reduction in the size of the LGNd and LGNvl in the mutant can be attributed to a decrease in neuronal population to a diminution of cell size.

Animals↗